First lady Michelle Obama talks with fashion designer Zac Posen during a fashion construction workshop session at the White House. (Jim Bourg/Reuters)

For a Wednesday afternoon luncheon in the State Dining Room, first lady Michelle Obama wore a sleeveless navy dress with a full skirt and a fitted bodice. It had a racer-style back and a sensuous front that showed off her shoulders. The relatively simple frock didn’t carry the weight of an inaugural gown but it was particularly significant nonetheless, because it was the dress she chose to wear to the first White House fashion education workshop.

The event was organized by the East Wing with the aim of giving a leg up to aspiring fashion designers and stylists, writers and entrepreneurs from 14 East Coast high schools and colleges. A significant portion of Seventh Avenue came to Pennsylvania Avenue to give the students a pep talk, including Jason Wu, Tracy Reese, Narciso Rodriguez, Diane von Furstenberg, Thom Browne, Reed Krakoff and Prabal Gurung. But Obama’s dress made it clear just whom she wanted to be the stars of the day: the students.

Her dress was imagined by Natalya Koval, a student from New York’s Fashion Institute of Technology, who was the winner of a design competition. A second winner, Chelsea Chen, another FIT student, had her design — a color-blocked sleeveless dress in green, white and navy — displayed on stage.

“When it comes to the fashion industry, so often people think it’s all about catwalks and red carpets and ‘who wore it best,’ and whether some famous person wore the right belt with the right shoes,” Obama said in prepared remarks at a luncheon for the students and visiting designers. “But the truth is that the clothes you see in the magazine covers are really just the finished product in what is a very long, very complicated and very difficult process.” Then she reeled off a couple of numbers: Last year, Americans spent $350 billion on clothes and shoes. And 1.4 million Americans are employed in retail and fashion.

“Fashion is really about passion and creativity, just like music or dance or poetry,” Obama continued.“For so many people across the country, it is a calling; it is a career. It’s the way they feed their families.”

First lady Michelle Obama visits the "Wearable Technology" workshop with workshop leader Cody Miller and fashion students. (Manuel Balce Ceneta/AP)

Before more than 150 students nervously eyed their lunch of chicken taquitos, miniature red velvet cupcakes and chocolate eclairs — “Eat!” implored a member of the White House staff — they’d broken into smaller groups for sessions on fashion inspiration, construction, journalism, wearable technology and entre­pre­neur­ship.

The first lady made short visits to the two workshops focusing on what are, perhaps, the least glamorous — but most essential — aspects of an industry that prides itself on its ability to sell dreams and magic. One looked toward the future in ways meant to be revolutionary but pragmatic. The other was a lesson in fashion’s fundamentals.

Obama walked into the Diplomatic Reception Room to the sound of gasps and a loud “Oh my goodness!” from the students. They were hunched over iPads, flashing LEDs and circuits. The only visible garment in the room was an otherworldly cream-colored gown strobing with colored lights. It looked more like an IT tutorial than one about design.

What they were doing, well, that remained a bit of a muddle. Led by Rebeccah Pailes-Friedman, a professor of industrial design at Pratt Institute in Brooklyn, the students created hockey puck-size devices that flashed lights at a predetermined speed. If there was a particular practical application, it was not clear. One could only glean the possibilities based on Pailes-Friedman’s interest in technology, sports and fashion and the sight of a woman standing off to the side wearing a helmet embedded with flashing white lights. It looked like the ultimate in night biking gear.

The designers who participated in the workshops represented a wide spectrum — from mass brands to high-end glamor to the more intellectual. Specifically, the design sensibilities ranged from Jenna Lyons of J. Crew and Maria Chen of the Gap, to the glitz of Naeem Khan and Zac Posen, to the mathematical allusions of Maria Cornejo and the allegories of Browne.

Missing from the workshops and, later, a panel discussion, were representatives of Seventh Avenue’s big three: Calvin, Ralph and Donna. The day really trained a spotlight on the generation of designers that emerged in the last decade, as well as those just starting out, such as Azede Jean-Pierre, who launched her collection in 2012.

The construction workshop had students crafting their own frocks on miniature dress forms — giving them a sense of the difficult task of fitting a garment and what it means to draft a pattern.

“That looks like something I would wear!” Obama exclaimed, as she surveyed the work of a group of students being mentored by Posen. It was unclear whether she meant a rather elaborate single-shoulder metallic bronze gown or a black tulle skirt that was barely more than a length of fabric. Both have antecedents in the first lady’s wardrobe.

Posen debuted as a designer in 2002 when he was only 21. His work, particularly his evening wear, is distinguished by its highly technical construction. Obama has been photographed in his exacting suits. But he is probably best known for this starring role as an impatient judge on Bravo’s “Project Runway.” He was a much gentler, almost paternal presence with his White House mentees, “Don’t ever put [pins] in your mouth,” was his admonition to one young man. “It’s a bad habit.”

Lela Rose, a favorite designer of former first daughters Barbara Bush and Jenna Bush Hager, was focused less on the technical aspects of garments and more on the romance — which wasthe focus of another workshop. But no matter: “We’re having fun,” she said, “and hopefully learning something.”

“We’re making journals,” Rose told Obama. “I was stressing how really important it is to record your ideas.”

The concept of a fashion education workshop has been on the table since at least May when Obama mentioned it at a ribbon-cutting at the Metropolitan Museum of Art, for the renaming of the Costume Institute in honor of Vogue editor Anna Wintour.

But it has taken decades for the fashion industry to once again be so prominently on view at the White House. Hillary Rodham Clinton recognized the industry’s philanthropy during her tenure as first lady. And in the 1960s, Lady Bird Johnson hosted a fashion show to celebrate American style and to goose the economy.

“When I used to come to D.C., I represented an industry that was considered decidedly unserious,” Wintour said in her introduction of Obama at Wednesday’s luncheon. “I was the lady in the funny clothes.”

Wintour credits Obama with helping to change that perception. “Fashion can be a powerful instrument for social change. . . . It allows us to think about who we are as individuals and as a society.”

And as for the first lady, who named Cornejo as one of her favorite designers and declared her affection for Spanx: “Fashion plays an important role in my confidence.”