When creating an audio book via the book creation wizard, there is the possibility to “clear” the image, and to choose another. This clearing deletes the file in question. (see 2nd screenshot) In actually becomes type “DELETED File” and is no longer selectable if one wanted to do so.
Semantically, I expected clearing to mean : clear the image on the left to make room for a new image. But perhaps it was meant like this. If yes, then perhaps a warning “after clearing, this image cannot be selected again” would be in order.