It's not possible as far as I know. At least not images based on artist. Views, yes. But not more granular I'm afraid.
It would be very handy to be able to store images of different media for back ground slide shows! There have been several requests for it. Stored in a similar way to the Themes perhaps. Broken up in Media Sub Type, then Artist name if artist, Series title if TV Show, Movie titles if Movies and so on. With an option to download todays files from Internet, you could go through the folders and look for non appropriate or ugly images, and use your favorites for all eternity. That would be something. Including backup of this images would be great. Perhaps a separate backup file if this takes a lot of space?
This could be used for backdrops for movies, tv shows etc. There is plenty of people that thinks this should be a standard part of Theater View today, and as we are probably getting better support from themoviedb.com soon(?), this is something to think about and plan. Not only automatic downloads, but customizable backdrop art folders for the neat freaks like my selfs.