The second of three films that Burt Lancaster made for producer Mark Hellinger who discovered the former acrobat and turned him into a movie star. The first of these was Robert Siodmak's "The Killers" in 1946, and the last, "Criss-Cross" in 1949, also for Siodmak, a film Hellinger never lived to see, as he died before production began.
The calendar girl was painted as a composite of all the female characters in the film: it features one or two facial characteristics from each of them. Therefore, when each man looks at it, it does actually resemble his loved one. The original prop was sold at an auction for $2,500.
The movie the inmates are watching is Io e l'uovo (1947), starring Fred MacMurray and Claudette Colbert. Both of these films were Aug 1947 Universal releases, and so it was a sort of a movie "trailer" within another movie.
This caused quite a stir in 1947, shocking audiences with its levels of violence.
The unsettling "calendar girl" everywoman the inmates have pinned up in their cell was painted by John Decker, who, among other things, did the paintings in Fritz Lang's La strada scarlatta (1945).