It was done in the 1940’s so the demons might be due to WWII.
A wildboar, a baby over a horse and a warrior can be spotted clearly but, apart of a goat with horns (that is not looking at the spectator and could just be a hunting scene), none of the stereotypical figures associated to demons like stars, 666 numbers, or inverted crosses are seen in the photos
If there are demons, they look much more like Asian demons. Not in the christian tradition at all.
Those are modern, pop culture stereotypes. The inverted cross and the pentagram are centuries old catholic symbols (not associated with demons).