Comment 3 for bug 1428076

That sounds like the case here indeed! Since after initial changing of the wallpaper, the scaling values seem to be good for both screens. After a reboot though I guess it's simply saving and using the scaling value of the left-most monitor (in my case, the smaller one), making the wallpaper ugly.

Thanks for the info. It's certainly no priority, as I suppose my use-case is rather specific ;) I might look into that later.