Leaning in close to the mirror, peering over the top of his glasses, Hockney stares so hard at himself his eyes are nearly glazed with looking. He is painting himself literally in the act. The brush, which he cannot see at this precise moment, is forming a line out of the very watercolour from which it is made. A blot of black has escaped. Hockney, virtuoso draughtsman, great technician in every medium from oil to print to coloured crayon, is challenging himself with quick-drying, no-corrections watercolour. The picture is almost life-size. Hockney is putting himself on the spot.