Jason Wu has gotten quite chummy with Stephanie Seymour of late. The fortysomething model, who vamped in the front row with her sons Peter and Harry today, stars in the designer's Spring ad campaign. You can Google an Inez and Vinoodh-lensed picture of Wu with his head practically in Seymour's bare-legged lap. Then there's Michelle Obama, who chose a dress by the designer for her husband's second Inauguration Ball last month, four years after she wore a Wu gown to his first, although you won't find any snapshots of the two of them palling around at La Grenouille.

Anyway, those fruitful relationships could be why Wu set out to design what he called his "most womanly, most grown-up" collection to date. He called it Extreme Femininity, and he definitely set a glam scene at his Park Avenue venue, installing a massive chandelier in the middle of his square runway. In the past, he preferred whimsy—remember those KAWS-designed prints? Here, he opted for its opposite. The shoulders of his power suits certainly were assertive; they were as strong as waists were nipped. Shirts, meanwhile, were buttoned all the way to the top, with collars just grazing the chin. You couldn't call the collection restrained, not by a long shot, what with all that fur (best as black patch pockets on a caramel brown parka) and the provocative lace-printed clear plastic trenches. But the black and white color palette, with only a few shots of red (a nod in Mrs. Obama's direction?), seemed to be Wu's way of saying, "I'm getting serious."

All grown-up or not, a girl still likes to let her hair down from time to time. Ask Seymour. Wu was at his most convincing here when he focused on the "femininity" of the show's title: the swingy pleats of cocktail dresses, the polka dots of a sleeveless blouse, charming point d'esprit camisoles with long trains worn over capri pants. Those were in his sweet spot. He strained harder to incorporate the "extreme" into his sensibility; in the end, that part isn't such a good fit.