Comment 2 for bug 1567287

I see same problem after upgrading. Scripts that were written with idea that the laptop built-in display is always LVDS1, as it always was, no longer work. More bothersome, the assigned value of the monitor in xfconf-query statements seems to change, depending on what is plugged in.

This does work now

xfconf-query -c xfce4-desktop -p /backdrop/screen0/monitor0/workspace4/last-image -s /usr/local/share/Backgrounds/Animals/animals_lion-bcd2e615_dbg.jpg

but in previous the "monitor0" was "monitorLVDS1". In fact, now that I check my notes, I realize all of the monitor bits ended in 1, "VGA1", "HDMI1", and so forth.