Fashion pop ups in unlikely places

While wandering back from a meeting with a hedgie on Haymarket, I noticed a banner emblazoned with the logo of Browns, clothes shop to the well heeled (to mix metaphors), above the entrance to what appeared to be a building site. It was indeed a building site, off Marshall St, near Carnaby St, but two floors of the new apartment block there have been taken over by a pop-up exhibition to celebrate 40 years of Browns.

Browns, ever since it was taken over by Joan Burstein in 1970, has always been one seam ahead of the pinking shears, which is why a pop-up museum makes perfect sense, although the whitewashed walls and pine floorboards are a world away from Browns' luxurious flagship shop on South Molton St in Mayfair.

There is as much self-love here as at the Grace Kelly exhibition at the V&A - you can't spell 'fashion' without 'onanism' - but Burstein was a fashion revolutionary rather than a clothes horse. She introduced the concept of the boutique with multiple designers, and brought over American houses like Ralph Lauren and Japanese ones like Commes des Garçons. Galliano, McQueen and Chalayan are other finds.

Mannequins are adorned with outfits drawn from the Browns archive and large portraits show celebrities wearing them: Iman in Armani (or whatever). There are blown-up magazine spreads from Vogues past and even a news clipping by Mollie Parkin from soon after Browns' inception.

This may seem frivolous - and indeed my only connection with fashion is having watched The Devil Wears Prada 15 times - but it is a thoughtful show, well curated, with archival material, which mixes the paradox of fashions past with a very modern instantiation.

• Browns: 40 Years of Fashion Innovation is on at The Regent Penthouses and Lofts, The Courtyard, 16-18 Marshall St, London W1 until 30 May. Hurry!