Cindy Sherman, Sprüth Magers

I don't think I've ever seen quite so high a patron:picture ratio as at the Cindy Sherman opening at Sprüth Magers on Grafton Street last night. The gallery verily overflowed with an unaccustomed mixture of Mayfair and Shoreditch, spilling out onto the street where neon t-shirts rubbed shoulders with tailored suits, all to see three pictures.

They are very good pictures, of course, and the attraction en masse was easily explicable. Cindy Sherman is an alchemical mixture of reality and fiction: she photographs portraits but they are not of real people; she is her own subject, but she is always heavily made up as other people; she has realistic settings but they are blurred or digitised; they are in gilt frames but they are modern productions.

These are not simplistic oppositions, the facile sarcasm which is so off-putting in certain artists. Literally and metaphorically, we want to get under Sherman's skin, to explore the difference between her false face and her true one.

I actually find Sherman's pictures much more psychologically intriguing than most traditional portraits, but that of course is because they are designed to be ambiguous rather than aggrandising or beautifying. We have to ask what sort of woman is portrayed, and what sort of woman would want to be portrayed that way.

The intense fictionality of Sherman's pictures runs alongside their truthfulness, and the gap between them is where she leaves the viewer, wondering.

• Sprüth Magers, 7A Grafton Street, London, W1S 4EJ