A shining, silver paillette-encrusted trenchcoat sparkling on the runway as metallic confetti rained down: This is the memory London fashion week will have of its 25th anniversary—and the Burberry show that ended it. There was more young glamour per foot here than the city's ever witnessed in a front row. Emma Watson was present, and so were Gwyneth Paltrow, Mary-Kate Olsen, Victoria Beckham, and Daisy Lowe; Freida Pinto and Dev Patel were holding hands. And every piece Christopher Bailey showed could have been worn by any one of them: The message was Burberry gone short, draped, deluxe, and glamorous, and aimed at the very young.

Returning from Milan to London could have meant a wallow in heritage nostalgia. Not a bit of it. Instead, Bailey brought all the high-gloss international production values he knows back to his home city, and made sure the label's history—namely, the iconic trench—looked alive and relevant to the 18- to 25-year-olds in the audience. From the fashion point of view, the reinvention of the beige, military-inflected coat is perfectly timed. Not only are tones in the range of camel and nude spot-on for the season, but military references are cropping up in many places as well.

Bailey's way of developing it had nothing to do with anything as dull as the English weather. All the emphasis was on building up a glamour shoulder, with a tied reefer's knot on the upper outside edge of each arm. All kinds of sexy tulle draping, meanwhile, were worked into what went on below. Having neatly scooped up those trends (along with a passing pastel moment), Bailey took pleasure in teasing out yet more possibilities. He showed some of the incredible techniques and fabrics Burberry has access to, like silvered gabardine and sliced suede made into hot leggings. In the end, though, this show may be most significant for the way in which it closed the gap between a public and private fashion event. In the front row, Paltrow, Pinto, and Patel were wearing pieces from the outfits that were walking the runway. And at Burberry's flagship in the center of London, the show was being Livestreamed to the public.