The handprint in the lower left panel corresponds, in a loose sense, to the inclusion of a hidden fingerprint in the "Unknown Masterpiece. The mysterious cufic inscription* in the upper right panel of the print, which is normally only visible as a detail, relates to a similar inscription which appears to have been inscribed upside down on Olga's sleeve.
Magical alphabets are a tool of both magician and alchemist, it is very likely, knowing Picasso, that these mysterious inscriptions have been composed in such an alphabet. Unfortunately the meaning of these inscriptions, without the cipher, is impossible to ascertain.
* As noted by Alfred Barr in, "Picasso, Fifty Years of His Art," 1946.