Justin Mortimer, whose exhibition "Shopping a Londres" opened in London last week, is having a very successful decade. He's only 27, but already has three solo shows and the BP Portrait Award under his belt. He's painted portraits of Harold Pinter for the NPG, Mr and Mrs David Bowie for themselves, and, most recently and prestigiously, the Queen for The Royal Society of Arts.

This last commission was officially unveiled last week, though the chorus of disapproval was sung some months ago when the Sunday Times sneaked a preview and the tabloids followed suit. Their objection was based on Mortimer's depiction of the Royal head: blue rinsed and slightly blurred, and not quite aligned to the Royal body.

The Queen, of course, is a difficult subject (she probably says the same of Mortimer), but it must be hard for a young artist to stand up to the inherited and rather tired conventions that surround the very idea of a royal portrait. To his credit, Mortimer stuck to his usual style. The result is not a great painting, but it is a brave one and rather more interesting than some that we've seen of Her Majesty in recent years.

The rest of the pictures in Mortimer's new exhibition, "Shopping a Londres", take their theme from the world of mail-order catalogues: from little girls in summer dresses - "our buyer broke down and wept when he saw these pretty frocks at such crazy prices" - to a world of "inherited disorders" and "worry-free genetic counselling". All rather odd (the point being, I think, that darkness lurks beneath the sunny scene), and very stylishly done.

Appropriately, the show comes with its own snazzy publication picturing Mortimer on the cover: hands on hips and face staring out, his portrait of the Queen propped, casually, against a wall behind. It's a pretty arrogant pose, but one that is tempered by humour in both the text and the pictures. He's an able and often sophisticated painter whose career should be worth watching in the years ahead.

Shopping a Londres, The Blue Gallery, 93 Walton Street, London SW3 (0171- 589 4690) to 18 April