There is a similar structure to both compositions and the protagonists in the depicted scene, are almost identical.
The flower girl holding a candle, is basically a transformation of the figure of Olga in "The Unknown Masterpiece," suddenly reappears in guise of innocence and as a protective force against the blind Minotaur advancing from the right. The enjoined figures of the wounded horse and Marie-Thérèse wearing Olga's bullfighter's costume, are again direct transformations of the characters and action in "The Unknown Masterpiece."
Again Marie-Thérèse is personified as the wounded horse in the bullfight.
There is a direct positional relationship between the Minotaur with the massive hidden bull on the right in "The Unknown Masterpiece and between the horses which occupy the central ground in each of the two compositions.
The Christ-like figure climbing the ladder in "Minotauromachy" is the crucified figure on a ladder in "The Unknown Masterpiece." In each case the figure is identifiable as Picasso, in his Christ-like alter ego.
The flower girl's burning candle recurs as the flame-like motif in front of Olga, who is depicted in "The Unknown Masterpiece" with a bunch of flowers concealed behind her back.
In addition, the sinking sail-boat on the horizon in Minotauromachy relates to the marine motifs in "The Unknown Masterpiece" as the two birds perched on the window ledge, relate with it's two concealed owls.
Interestingly, the small building on the left of the print, is closely related to the burning building in "Guernica." It is reminiscent of a small puppeteer's theatre, which in turn, relates to the numerous puppetry allusions in "The Unknown Masterpiece."
As can be seen from the above list of correspondences, the relationship between the two compositions is a deeply interconnected one.