Picasso, who was himself, often described as a monster, loved cinema and almost certainly saw 'Frankenstein' soon after its release in France. It appears clear from the drawing that Picasso went on to identify a number of symbolic links between himself and the monster and identified further symbolic associations between the monster and Hitler's Aryan Superman.
Frankenstein's monster, like Oedipus and Picasso, were in a sense all responsible for the destruction of their fathers*. All three also suffered a form of blindness; Picasso symbolically, Oedipus by self infliction, and Frankenstein's monster at birth when his eyes are extremely sensitive to light.
All three also underwent a form of crucifixion; Picasso symbolically, Oedipus when he is exposed on the hillside by his father, the monster, both when he is created and when he dies under the sign of a burning cross. Finally, all three characters also experience the pain of exile; Picasso at the turn of the century, and again in the 1930's, in protest against Franco, Oedipus by his own edict, and the monster by his being violently ostracized from society from the day of his creation.
The Hanged Man symbol, with which Picasso closely identified, also features in the Frankenstein movie. In an early scene, parts of a murderer's corpse are stolen from a gallows, to be used in the creation of the monster.
A further association involves the monster's huge fee, which Picasso would have related, in an instant, to the 'Swollen Feet' of his alter ego Oedipus.
The only real human contact the monster makes is with a little girl called Maria who picks some flowers and offers one to the monster. The flower girl is another important psychological symbol, for Picasso, which is present in numerous important works. In the movie, after the monster inadvertent kills the flower girl, she makes a second symbolic appearance, in the guise of Dr Frankenstein's bride, holding her wedding bouquet.
The concealed portrait of the monster in "The Unknown Masterpiece," appears to have its right eye hanging out, a detail that links him symbolically with Odin, who put out one of his eyes and hung inverted from a tree, like Oedipus.
In regard to the concentration of Germanic themes, such as Frankenstein, Wagner and Odin, there is a further level of interpretation which seems to be preoccupied with the rise of Hitler and the Third Reich. In "The Unknown Masterpiece," Picasso, in the time-honored tradition of Daumier, appears to identify the dominant force, Olga, with Nazi Germany, making a deceptive and vicious attack on the helpless victim, Europe, on the left.
* The death of Dr Frankenstein is alluded to but left somewhat ambiguous at the end of the movie, presumably in order to have a happy ending.