Both "The Unknown Masterpiece" and "Guernica," contain similar inversions of fish and bird imagery. In "The Unknown Masterpiece," a concealed bird is standing upon a fish's head, and in "Guernica" a fishes body is hidden above a concealed bird.
The inversion is almost certainly derived from the mystical ballet, "Uspud," written by the Picasso's close friend, Erik Satie, in 1892.
In Satie's play, an extraordinary crucifixion takes place featuring, "fish bodies with the heads and wings of birds" and other strange animal and demonic creatures, a number of which also make an appearance in "The Unknown Masterpiece."
For further information about this connection please read the following sections: