He's sitting on a model yak, in his right hand (for the viewers left) he's got an emtpy bottle of Inca Cola, in his other a packet of foreign Camel cigarettes. Of course there's the inevitable Pink Floyd photo book and the console thing lying on the Yak's head might just be the infamous Konix Multisystem.
This photo was used to make artwork for an end-of-level monster in Thalion's game "Leavin' Teramis". At the end of a level there was Jeff Minter's head (drawn from this picture by Michael "Mickey" Grohe) and there were dozens of little llamas coming at you that you'd have to obliterate (if only Jeff knew).