Comment 6 for bug 1325505

System Settings should be using a background file location that the greeter can read, not a location inside the user's directory. This is what the XDG_GREETER_DATA_DIR variable is for. It's a folder where the user can share larger files with the greeter.

I fixed telephony-service to use that folder for avatars, but I overlooked the background file use case when splitting the greeter, sorry.