This masturbation symbolism is strongly implied by the painter's hand positioned suggestively upon the erect handle of the paintbrush in the area of his loins.

There is also the strange recurrence in "The Unknown Masterpiece" (detail bottom right) of a distinctive shape like a dark pointed animal eye or demon's eye which seems to be the same eye depicted in two of Picasso's 1932 crucifixion studies. (details below and bottom left.)