I think it might be useful to have images only available for viewing by an authorization list, and not all authorized users. The reason for this is because I typically use authorizations for mutuals so that they can view my unwatermarked images, and I might not want all of them viewing certain images, if that makes sense? Instances where this could be useful are maybe personal/vent art only viewable for lists of close friends, nsfw art only viewable for lists of 18+ users/friends, etc.? This has probably already been suggested in the past, but I couldn't find a thread about it.
This is already a character privacy feature, I'd love to see it for images as well! ^^
This isn't the precise feature, but the solution I use at present is sub-galleries! You can set up a sub gallery that's still part of your character's main gallery, but that section will only be visible to people you authorize, the same as with character permissions:
