Originally Posted by D1ver
I'm not sure if this is related but I needed to add
To get a script working as a cron job that used feh to change the background. Maybe gxmessage doesn't know which screen you're asking it to display on?
After thinking about it, that might be the issue. If running from a standard terminal, of course it wouldn't work, but exporting the DISPLAY environment would definitely tell it to use the first X server that is allocated on the OP's system.