Very true but it begs the question of generic picture management policy.

Unfortunately, even if there are very few changes to the images, git does badly with giant binary blobs. It's true that does *worse* if the images are edited heavily, but, really, for things like this you don't want *any* extra copies of the images lying around, and git's going to give you one every fifty-odd commits, as long as there's a modification in there somewhere.