See.. adblock+ blocks other stuff from the same site. If I tell adblock+ to not do that ("whitelist"), then it blocks NOTHING.
It seems to lack a way to block just one specific .jpg.
When I right click an image and then select Adblock Image, the first option is a complete URL including filename and it only blocks that specific file. Other files on the site don't get affected.
I think I know what you mean now. The site you want is normally blocked by the Adblock filters and you want to whitelist the site but only block a specific image? In that case then I don't think it'd do what you mean.