The background menu was missing "centered", "maximized", and "filled".
This closes Debian bug #85591 [1]:
The current default for the scaled backgrounds menu is to use
scaling without keeping the aspect ratio.
This very rarely yields to a usable background.
Could the default be changed to scaling with keeping the aspect
ratio ?
[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=85591