References used by artists vary far and wide, but to use two separate images from a 1932 horror film for the jacket of a book that was published in 1946 is, I think, unusual.
The Sun Queen, a British science fiction/fantasy novel written by H. Kaner and presumably self-published (it was printed by Kaner Publishing), dealt with a kind of thought travel to the sun. It garnered only tepid reviews and was even negatively described by an online bookseller, which is not exactly a good way to peddle a book if you ask me.
The jacket was painted by H.W. Perl. There is scant biographical information regarding the presumed "Mr." Perl, but there are several more examples of his work depicted on the web. In particular, a site called Look and Learn Picture Gallery has a number of Perl's book cover works, including covers for supernatural-themed books.
The cover of The Sun Queen shows obvious references to Zita Johann as Ankh-es-en-amon and Boris Karloff as Im-Ho-Tep as they played in Universal's THE MUMMY. The poses are from publicity photographs at the time of the film's release.
It appears than Perl may have had a "Zita Johann" reference file. Among the waterarked images from Look and Learn is a book cover of the novel, Frightened Virgin (!). The pose on the cover painting of this book looks quite similar to that of the poster image from THE SIN OF NORMA MORAN, another film that starred Zita Johann.
Mere coincidence . . . or . . . sinister simulacra?