Here’s an article about the Soviet photographer with more photographs:
https://www.anothermag.com/art-photography/9377/the-clandestine-soviet-photographer-taking-nude-portraits
Here’s an article about the Soviet photographer with more photographs:
https://www.anothermag.com/art-photography/9377/the-clandestine-soviet-photographer-taking-nude-portraits
It is the lighting from her neck up. Perhaps that is a style from the photographer, but it looks almost like her head was photo on to me.