She's become known for a playful, happy kind of cool, and Stella McCartney's latest collection furthered her easygoing cause with a deft assimilation of the season's trends. She started out with a long, flowing seventies dress in a wildflower-scattered silk voile, loosely tied at the neck, then used the same colorful fabric for the jumpsuits her label is so identified with. Doing her bit for the current pajama-dressing moment, she showed boxy blue silk pj tops with tap pants peeking out from beneath, or extended the top's hem a few inches down the thigh for a reinterpretation of her favorite shirtdresses.

Many of the white cotton frocks, with their dippy backs and suggestive ruffles, could've been nightgowns in a former life—but McCartney balanced all the dishabille with the blazers that she cut her teeth on in Savile Row, this time in a safari khaki or in double-breasted snow-white, worn with fluid, full-to-the-cuffed-ankle trousers.

The designer has a well-known dedication to vegetarianism and the environment, and the show's backdrop, a lushly beautiful "vertical vegetal wall" by the botanist Patrick Blanc, will be donated to a low-income housing project in Boulogne, part of an effort to help teach ecology at street level. The carved wooden clogs she asked her models to wear won't make it on the street, however: One pair didn't even make it up and down the runway before falling apart. But that's not of much consequence when the clothes are as pretty and wearable as they were today.