Jenna Lyons is in her corner office sucking on an iced coffee as if it were manna. The room looks like a cross between a boudoir and an artist's loft, with a peach fur draped over a white leather eames chair. The industrial windows stretch up and up, like Lyons's legs, which are punctuated by a pair of metallic, sparkled 3-inch stilettos. But the coffee just isn't cutting it. "I'm so hungry. I haven't eaten in 10 days," says the executive creative director and president of J.Crew, not hyperbolically. "I was like,errrr! errrr! with every pair of pants," she adds, making that grunting sound familiar to all women at some point in their lives. Turns out even the most fashionable manager in America can have a bad clothing day. "The inside button would pop before I even zipped it. I was like, Oh, God!" So Lyons went on an organic-juice-cleanse-plus-Isogenics bender and has consumed nothing but liquids for more than a week. "I'm a little bit mangry. Hangry mangry," she confesses, within five minutes of my arrival.

It's surprising, though comforting, to find out that Lyons is humanly imperfect. Since her coronation as creative head of J.Crew in 2008, the company once known for its preppy Nantucket ancestry has become a force in fashion, with Lyons at the center of its evolution. She has created a high-low look that reflects her own boy-girl style--androgyny with some sequins and a dash of nerdy glasses. Along with annual revenue that has more than tripled to $2.2 billion since 2003, the cult of J.Crew has blossomed like a CMO's fantasy, with fashion blogs wholly devoted to the brand (from JCrewIsMyFavStore to TheJCRGirls) and a fan base that includes Michelle Obama and Anna Wintour. At Fashion Week this February (J.Crew's fourth season there, itself a symbol of the retailer's growing influence), one attendee whispered, as if Lyons were Madonna or Bono, "I am just totally obsessed with Jenna."

Her ascension seems instantaneous, but she happens to be one of the company's longest-tenured employees, having worked there her entire career. After graduating from Parsons in 1990, the then 21-year-old started as an "assistant to an assistant to someone else's assistant," as she puts it, designing the company's old-world men's rugby shirts. "It's taken me years to get here, and I've cultivated it so carefully," says Lyons. "But I didn't think it was possible. I just assumed I'd plateau and that there would be no place for me to go."

She most likely would not have reached her perch if she hadn't crossed paths with Millard "Mickey" Drexler, the son of a garment district fabric buyer, the so-called Merchant Prince who transformed Gap from a $400 million enterprise into a $14 billion empire. Not since Steve Jobs and Jonathan Ive at Apple has a creative pairing been as intriguing and fruitful as that of Drexler and Lyons. Drexler became chairman and CEO at J.Crew in 2003, four months after Gap fired him following a plunge in the company's stock. His fall was both humiliating and motivational. Todd Snyder, Drexler's former head of men's wear at Gap, advised him to seek out Lyons, at the time J.Crew's vice president of women's design, likening her to Calvin Klein in the early days. "Jenna was a great designer, she looks like a model, and then she talks like the best salesperson you ever met," says Snyder. "I think she's the most talented person he's ever worked with in design."

Their partnership would mark the end of the days when J.Crew's product design was dictated by corporate strategy. Together, they would make and sell only what they loved. The love would not be unconditional; they would adjust their product line always, trying new ideas, assessing, and quickly getting rid of anything that didn't work. Under Drexler and Lyons, J.Crew would become a company of constant and freewheeling experimentation, iteration, adaptation.

On the surface, the two are an unlikely fit--Drexler, a 68-year-old from the Bronx; Lyons, a Southern Californian who at 44 looks like a J.Crew model before the airbrushing. Yet they share an ebullient, unself-conscious nature, and they have set the standard for running a business focused on design. Though he is a notorious micromanager, Drexler doesn't stifle the talent, funneling his obsessiveness toward the steps that come before and after the creative process. And though she has been called a designer's designer, Lyons has instinctive business acumen. In Lyons, Drexler has found a partner to create both an ethos of mutual support for creative risk-taking and a unified aesthetic that suffuses the company and is spreading through the culture at large. Which is how Lyons came to have the unusual dual role of J.Crew's top creative executive and its president. "What it says," Lyons claims, "is that no financial decision weighs heavier than a creative decision. They are equal."

J.Crew employees reveal themselves by the nakedness of their ankles. It's as if the company's uniform, ambiently dictated by Lyons, is enforced only from the knees down. Bare ankles, for men and women alike, whether with suede bucks, ballet flats, heeled ankle boots, high-top Converse, vintage Nikes, or glittery pumps, fill the company's East Village headquarters. At a review in early March for a jewelry catalog shoot, sockless stylists, art directors, and merchants gather before Lyons as she interprets a wall mocked up with outfits paired with samples from the company's latest accessories collection. "This--not so pretty," Lyons says, her delicate hand clasping a chunky turquoise necklace hanging at the neck of a white linen suit. As she continues along the wall, her underwhelmed reaction becomes increasingly apparent. But instead of pointing fingers, she senses a deeper problem, and the jewelry review turns into a mediation session. "It seems like you guys feel you didn't have a lot to play with?" Lyons asks. The stylist agrees. Lyons starts probing to figure out how the stylists gain access to jewelry for a shoot--which is just where the problem began.

"When something hasn't been as beautiful as it can be, the reason is always bigger than the thing," Lyons tells me afterward. Here, the reason was miscommunication between the stylists and the merchandisers. "At this stage, I'm like a glorified crossing guard," says Lyons. "It's like, try to keep people motivated, keep the traffic moving, keep people from getting stumped or stopped by a problem."

She has a therapist's touch as well. "Every time I walk in her door, she reads my mind in three seconds. I think she knew I was pregnant before I did," says Ashley Sargent Price, who does art direction for J.Crew's catalogs and website. "She knows how to make you feel appreciated, even if you need to be redirected." The skill is an essential one for getting the best out of designers, who, Lyons holds, don't operate by the same rules as other people in business. "Managing creative people--not so easy," she says. "A lot of emotion, a lot of stroking. Some people need tough love. Some people need a lot of love." Above all is the challenge of managing in a subjective realm. "There's no right or wrong answer," says Lyons. "When someone creates something and puts it in front of you, that thing came from inside of them, and if you make them feel bad, it's going to be hard to fix, because you've actually crushed them."

This sensitivity stems in part from a challenging childhood. Lyons was born with incontinentia pigmenti, a genetic disorder that led to scarred skin, patchy hair, and lost teeth, requiring dentures as a kid. Her gawkiness (she's now 6 feet tall) didn't help. As a result, she was subjected to almost constant bullying. "It's amazing how cruel kids can be and superjudgmental and really just downright mean," says Lyons. Her nonchalant manner became her defense, and she found a refuge in art. "I searched for ways to make things more beautiful and surrounded myself with beautiful things because I didn't feel that in myself," she says. Her mother, a piano teacher, encouraged Lyons to take art classes, where she discovered a passion for drawing and sketching and what might seem to be the unlikeliest of interests--fashion. "I felt a huge drive to make clothes that everybody could have because I felt ostracized by that world of beauty and fashion," says Lyons. "I never thought I would have a part in it. Never in a million years." She traces her ambition to her parents' divorce when she was in the seventh grade. "I'll never forget my mother standing in the tuna-fish aisle thinking, Are we going to get tuna fish this week?" says Lyons. "Feeling like I never wanted to rely on a man, I was like, I gotta work my ass off."

It was Lyons's candor that initially impressed Mickey Drexler. When he arrived at J.Crew in 2003, the company was in financial distress and largely seen as a bit player in the industry. Management consultants had taken over and were prescribing product designs. On Drexler's first day, recalls Lyons, "he sat down, pushed his chair back, put his foot up on the table, and he looked around and he's like, 'You're all interviewing for your jobs.'" On his second day, he asked Lyons to run through the women's collection in front of the entire team, a roomful of 50 people. She presented three pairs of skinny stretch pants. Drexler asked what she thought of them. "At that point I was like, I have to be honest," recalls Lyons. "I can't lie to him because this is sort of a do-or-die situation." She said except for one pair, she didn't think the others fit the brand. Drexler told her to throw them on the floor. Then they got to a boucle sweater, which looked like poodle fur. Lyons said she hated it, but it was a million-dollar seller. Drexler told her to drop it on the floor. Then came the cheap cashmere T-shirts, made in China. Onto the floor. "I didn't know if I was going to be fired," says Lyons. "I was so confused, and I was scared, but I was also a little bit excited, because all the things that I liked and that I thought were brand-right he was leaving up on the wall. And I was like, Is that good, is that bad? I don't know."

She kept her job. (Many of her colleagues did not.) After two days of reviewing the entire product line, Drexler told Lyons to get on a plane to Hong Kong and design new pieces to fill all the holes. He also asked her where she wanted to source the company's cashmere. A more expensive mill, she said. He told her to call them. This move marked the beginning of Drexler's turnaround strategy--a bet on quality. "You cannot copy high quality, and it takes a long time to get a reputation for quality," he says. Lyons credits this first encounter as both formative and telling of their future together. "Honestly, I think it was because I didn't bullshit him," says Lyons. "His bullshit-dar is insane."

Giving primacy to design involves more than a shift in the power structure. It means running the business in a completely different way. Before Drexler came to J.Crew, designers were ordered to develop products that would meet specific merchandising goals. "We were told we need 'this bucket' and 'this bucket' and 'this bucket,'" says J.Crew head of women's design Tom Mora. "'I need a merino sweater that is $48 that has a stripe.' And you are jamming your design into a bucket and that's what you got--a design in a bucket." Drexler told Lyons not only to scrap the buckets but also, she says, "'Don't tell me what you're doing, don't show any of the merchants, just go and do it and then show me.'"

In generating those designs, Lyons's style and manner give her staff implicit permission to take risks. "Jenna leads by example," says a former J.Crew employee who worked for Lyons in men's wear. "She'll be wearing an oversize men's cashmere sweater and a maxi skirt of feathers. If you described it to a famous fashion person, it would sound ridiculous. But it's liberating for everyone who works for her." Three years ago, J.Crew designer Emily Lovecchio floated an idea for an organza jacket. The fabric was unusual for such a garment because of its delicacy, but Lyons told the team to try it anyway. The jacket ended up on the cover of the J.Crew catalog. When experiments don't work out as well, all Lyons requires is for her staff to assume responsibility. "Jenna really loves people who are themselves, flaws and all," says Lovecchio. "If you mess up or totally do the wrong thing, you have to look her in the eye and say 'I messed this up,' and she will always say, 'Okay, we'll fix it.'"

Designing distinctive clothing was only the first step in reviving J.Crew. Lyons believed that to create a coherent brand and drive the business forward, every piece of the creative organization--from retail to catalog to web--had to be unified. She was initially frustrated that the stores and catalog, both run by merchandising, didn't match the aesthetic of the products. "There were a lot of really talented people, but they were all doing their own thing, and it looked like it," says Lyons. "It was bifurcated and fractured. It didn't come together." While Lyons is a little coy about whose aesthetic she felt the company needed--"It's not that my vision is better. It's having one singular vision"--she ultimately did fight for it to be hers. "For me, it was like, 'I really want to get my hands on that because I want it to look more cohesive, and it's driving me crazy.' So I was asking for it," says Lyons.

In 2010, her lobbying paid off. J.Crew's president, according to the official announcement, stepped down "to spend more time with her children," and Drexler gave the title to Lyons. "It was literally a two-second conversation," says Lyons. "He pulled me into a room and said, 'So, just want to let you know you're the president.' I was like, uh, okay. Alrighty then. Then I put my head down on the table, took 10 deep breaths, sat back up and was like, 'Okay, do I need to do anything different?' And he was like, 'No, just keep doing what you're doing.' I'm like, 'Okay,' and we walked out of the room. That was it."

As Lyons's domain within the company grew, the prime directive for all her teams became always to consider how the brand appears to everyone who comes into contact with it. "I don't care if it's an employee handbook or the layout of the nursing room," says Lyons, who now also oversees marketing. She started with the stores. Their design, she felt, clashed with itself--sparse interiors with clothing stacked in chockablock fashion. "It's a little bit like a modern house with tons of shit in it," says Lyons. "It really doesn't look so pretty."

Lyons set out to rehab the stores, but getting the details just the way she wanted required her to make a business case for design. "It's hard when the finance team is used to putting a light fixture in the store that costs $2,000 and I'm like, 'Well, I want an $8,000 fixture,'" says Lyons. "You have to get people to understand why having that Serge Mouille light fixture is better, because it's beautiful and people will know something's different. Maybe when you look at that $200 cashmere sweater, you'll feel like, 'Oh, yeah, look at the store, it's so beautiful. This $200 sweater is a steal.'"

More recently, Lyons worked a bold overhaul of the catalogs. With 40 million copies distributed every year, the catalogs are at the root of J.Crew's business and constitute some of the brand's most precious real estate. Yet for years, the catalog lineup was dictated by sales from the year before. Pictures of each item ran alongside clunky color swatches and dense text; perhaps only 2 out of 100 pages were devoted to material that might be called editorial. The reimagined catalog supports the idea of J.Crew as tastemaker, with multipage stories packaged around trends, such as "The Italian Shoe Collection: Designed in New York. Made in Italy" for some fancy leather flats. Today, the J.Crew Style Guide--its new name--and its website have more of the feel of a fashion magazine.

Lyons's whimsical nature can sometimes make her seem like a different species from most folks with a key to the executive floor. And she can hardly be accused of stuffy qualities like propriety or perfection. "Ask my ex-husband how perfect I am," she jokes during one of our interviews. (He might have a thing or two to say about it, too; Lyons's personal life has been tabloid fodder since 2011, when she got divorced and paired up with a woman.) "You're pretty candid," I tell her. "Maybe to a fault," she says. "I might take my teeth out." Yet her colleagues credit her with a keen business mind, and that easy oscillation between her two selves is what has brought her so much success. Libby Wadle, J.Crew's executive vice president of brand (that is, merchandising), says: "Jenna is a designer all day long, but she can have conversations about real estate and parts of the business that many designers will just tune out. She gets all the moving parts and how they connect." When I ask Lyons how going private in 2011 helped the company, she immediately cites the freedom to invest more in IT infrastructure--not the first thing you'd expect to hear from a native creative. "It's hard to make those kinds of capital expenditures when you're public," she says.

Emil Corsillo is a denim nerd. A 33-year-old graphic designer, he has an affection for vintage American workwear of the sort worn up until the 1950s. In his spare time Corsillo collects samples; he even has his buddy bring him back replicas from Japan, where the style first experienced a comeback. In 2008, Corsillo became particularly fascinated with old selvedge fabric, a hallmark of the workwear movement. The selvedge mark--a heavy red stripe stitched along the fabric's edge--indicates that a piece of denim is high quality, made from an original loom. One day Corsillo was tooling around with a piece of selvedge cloth on his sewing machine and realized that it was the perfect width for a men's tie. He and his brother Sandy would use the fabric in the Hill-side, a line of ties they launched in 2009.

For the Corsillo brothers, the tie was an experiment. They wanted to start small, working out of their Bushwick, Brooklyn, apartment, and they restricted supply to three independent shops. Within two months, J.Crew somehow caught wind of it. "Somebody there found our ties at one of those stores and brought them to Frank [Muytjens, head of men's design]," recalls Emil, "and Frank got in touch with us and said they wanted to talk about carrying the collection in a couple of shops."

Bringing in products made by third parties was a new gambit for J.Crew, but one that Drexler felt could raise its profile. The design team saw no point in trying to re-create, say, a beautiful handcrafted leather boot, when a Minnesota company called Red Wing had been doing it for more than 100 years. So J.Crew cracked the door to outsiders. "We buy what other people do much better than we can ever do," explains Drexler of the outside collaborations, of which J.Crew has had more than 100. Playing curator was also a branding strategy. The retailer isn't making much from the 25 pairs of handmade Alden Revello Cordovan Longwing shoes it sells, even at $710 a pair ("You have to have 100 perfect hides to make that many. That's why you can only have 25 pairs," a J.Crew store manager explains to me), but they reinforce the idea that J.Crew is carefully selecting products on the shopper's behalf. "People love scarcity," says Drexler. And scarcity brings people to the stores to buy shirts and pants.

When J.Crew approached the Corsillos about the selvedge tie, the company was an unproven partner for outside brands. While most homegrown players would view this moment as winning the lottery, the Corsillo brothers were conflicted. "To be totally honest, we were scared and uncertain," says Sandy. For one, the two didn't have the resources to make goods for a national retailer. But more important, if the Hill-side was going to establish its fashion cred, selling out to a big retailer didn't seem like the answer. "It's like not wanting your favorite punk band to sign with a major label when you're a teenager," says Emil.

The Corsillos turned down a couple of meetings with J.Crew--until they got a call at 10 a.m. one morning saying that Drexler wanted to visit them at their place in Brooklyn. "I looked around our office," recalls Emil, "and saw Sandy's unmade bed and dirty clothes on the floor, and said, 'Would it be possible to come to you guys instead?'" At J.Crew headquarters, they gathered in Drexler's office, along with Muytjens and four other J.Crewers. "Very quickly Mickey said something like, 'Okay, we're going to order this stuff immediately and put it in the catalog, right?'" says Emil. "No one had told him that we had sort of said no."

After the brothers explained their concerns, Drexler told them that J.Crew was trying its best to behave like a tiny company. And he immediately proved his point. During the meeting, as he paged through a J.Crew catalog, he came across a sneaker from Tretorn. When Emil mentioned that he was a freelance art director for Tretorn advertising, Drexler asked if he thought J.Crew was selling the best model of the shoe. Emil said he preferred another, the men's classic. "Mickey got on the officewide intercom," recalls Emil, referring to Drexler's most melodramatic prop, a loudspeaker system that booms through the hallways at J.Crew headquarters, "and said, 'Who's in charge of Tretorn? Come to my office!'" The person in charge of Tretorn was asked, 'Are we getting these?' Twenty minutes after leaving the J.Crew office, Emil got a call from his boss at Tretorn asking if he had just been in a meeting with Mickey Drexler. Eventually the company ended up carrying that Tretorn shoe--and the Hill-side, too, which is now on its 15th J.Crew collection. "I don't know if Mickey said anything specific that persuaded us, but he's very charismatic," says Emil. "Basically, any worries we had about their intentions pretty much dissolved at that meeting."

The performance was undiluted Drexler, mixing efficiency with his unique brand of persuasion. In many ways, he is the Woody Allen of retail, his New York accent still thick as garlic on his breath, a desire always to be the omniscient narrator in the world of his creation, though his neurosis is focused on cashmere instead of death. Insecurity is a shared motivator too. "Mickey has such a chip on his shoulder for being fired at the Gap and raised poor," says a former employee. "That desire and anger make him unstoppable and relentless." As with a film whose producer is also director and star, Drexler is always working his audience while telling his cast how to play the scene.

On a recent visit to J.Crew's new Ludlow Shop at 50 Hudson, Drexler's id and ego were on full display. "I wish we had a couple customers," he announces like a dinner-party host with no guests, greeting some 12 of his top staffers for a monthly store walk-through. "Just kidding. We do [have customers]," he tells me. Drexler's mouth is an engine that never stops, and his irrepressible effusiveness defeats any attempts at self-censorship. The Ludlow Shop is an outgrowth of the Ludlow suit, one of the most successful products to debut at the Liquor Store, a one-off boutique in Tribeca that has served as a Petri dish for new products. "If you look at most department stores--I'm not going negative on department stores," Drexler says, then whispers, "but I am." He then shouts, so even the few customers roaming the store can hear, "I can't stand them!"

Lyons and Wadle are staring at a spread from the May 2013 catalog. They decide to kill it. The two pages show models wearing thick black glasses, colorful oxfords with ties, bare ankles in heels--Lyons's signature girl-in-her-boyfriend's-clothes look. "It looks too much like the copiers," grumbles Wadle, who keeps making vague references to a Daily Mail article that came out the previous day and has been irking the team ever since. When I get home, I dig up the piece: "Has J.Crew finally found a rival? Gap makes big comeback." It is the worst kind of story for J.Crew, lumping it in with Drexler's ex, a name that is practically forbidden in the office. "And with a smattering of quirky spring prints (like the cat symbols on a boyfriend-style shirt), colorful outfit combos and the use of some geek-chic spectacles," the article reads, "it seems Gap's $133 million profit increase may be thanks to some strategic styling lessons from fast fashion's reigning queen bee, J.Crew."

If Drexler has taught Lyons one thing, it's that in retail you're only as good as your last suit. But in their search for the next big franchise, an important part of Lyons's job is managing Drexler. In many ways she has become both his editor and translator. At any given moment, ideas and questions machine-gun out of him. Says Wadle, who worked with Drexler at Gap, "It's a constant, and none of us can keep up because we all have to be running the business. She [Lyons] is the ultimate filter." The challenge lies in knowing which of Drexler's ever-flowing stream of proposals to act upon. "If we executed every single thing he said, we would just be spinning," says Lyons. "What he's trying to say is, Have you asked yourself every single question? He's looking for the golden nugget all the time."

Lyons is one of the few people who can rein Drexler in. She typically waits until a product is in its final form before presenting it to him. "Sometimes his head is filled with 50 other things and he has an allergic reaction to something because he looks at it crooked or he just had a bad meeting," says Lyons. "And it's like, 'Okay, hold on. Don't look at that for a second. Let's redirect. I need you to calm down.' I swear to God there are maybe three people, one of them being his wife, who can do that."

Lyons might have this power because Drexler knows he could never do alone what they can do together. "If Jenna wasn't there," says a former employee, "J.Crew would be really good, but it would not be great. Probably a healthily run company like a Banana Republic." They give each other cover too. "Mickey wants to be so cool so bad," says the former employee. "Jenna is confident and cool and human and comfortable with herself and gives him the credibility he needs to be on fire. And he has her back in a way no one else can." I ask Lyons what everyone in the business wonders: When will she leave J.Crew to start her own line? She says it's not in the cards, at least for now. As she has said, she already is building her own collection, and she wouldn't be able to do so on her own. Her former colleague Todd Snyder argues that no designer in Lyons's shoes would ever have a reason to leave. "Mickey has given her enough runway so she can really make of it what she wants," he says. "They should just call it Jenna Crew."

And for that chance, she says that she's indebted to Drexler. "This is his last job, you know? He's probably not going to do this again," says Lyons. Whenever Drexler does decide to retire, she and Wadle are rumored to be in line to run the company. "I'll give it to Libby," laughs Lyons, feigning disinterest. "I'll sit in the corner and draw some stuff." As if Jenna Lyons has never been hungry before.