Why use special directory (/urs/share/xfce4/backgrounds)for wallpapers? Cant'you use more usual directory /usr/share/backgrounds?
Created attachment 4260 Load wallpapers from standard locations This patch has xfdesktop-settings load backdrops from the XFCE_RESOURCE_DATA wallpapers/ and backdrops/ as well as the usual xfce4/backdrops/. This should make it easier for the users to pick backdrops that they have installed.
Xfdesktop4.11 allows the user to select the folder from which wallpapers are loaded, so this bugreport doesn't apply anymore.