"Thelma" was the title on the invitation for Peter Jensen's latest presentation, and given his predilection for idiosyncratic muses, the imagination ran riot. A straw poll came up with a draw between Thelma of Thelma & Louise fame and the fifties character actress Thelma Ritter. But Jensen was actually looking much closer to home, at Thelma Speirs, who for the last three decades has been half of the formidable millinery duo Bernstock Speirs, and also a DJ girl about town. "I love being around her," Jensen said before the show. "She'll wear jeans and a mink coat during the day, then dress for dinner at night." She also posed naked for a magazine last year, so right away there was that subtext of subverted propriety that is Jensen's own specialty.

His muse was parked front-row center, so it was easy to compare his version with the real thing. All the models sported gray hair, like Thelma's. The first outfit was a cropped jacket worn with cuffed jeans, just like she was wearing. A sweater in Jensen's signature rabbit graphic paired with plaid pants also featured Speirs' non-gender-specific style of daywear. As far as dressing for dinner went, Thelma was very taken with the final dress, a column in cream and black crepe, accessorized with a "necklace" of flocked headphones attached by a string of pearls to the bodice of the dress. (The pink flocked loafers were a quintessential Jensen touch.) Bernstock Speirs—who else?—provided the rabbit-ear hats.

But where Thelma ended and Jensen began faded into unimportance as the show rolled on, simply because the aesthetic that the designer has so painstakingly evolved over his years just outside the spotlight was perfected here. Familiarity with it definitely helps. What might otherwise seem utilitarian (choose any smock-over-long-sleeve-shirt silhouette) and even schoolmarm-ish prim was continually undercut by an amused lightness of touch, surreal little flourishes (glittery belts; a gold fringe; a scatter of beading; a log cabin print; a beaded, flocked white shirt collar doing double duty as a necklace), and a twisted color palette that went deep on brown, chartreuse, and fuchsia.

Jensen is a generous designer, or at least kind. There has always been the sense that he might be dressing the girls no one else pays much attention to. No longer. Alexa Chung was at the presentation. She immediately picked an outfit—a black velvet dress with a beaded chiffon insert over a cream crepe blouse—to wear to the Brit Awards tonight. And she swore she'd be back for everything else.