sudo -u lightdm dbus-launch gsettings set com.canonical.unity-greeter background '/usr/share/backgrounds/mate/nature/ioi_terminal.jpg'
Changing the background on Ubuntu login
sudo -u lightdm dbus-launch gsettings set com.canonical.unity-greeter background '/usr/share/backgrounds/mate/nature/ioi_terminal.jpg'
Note: This post may be AI-assisted and then human-edited. Editorial responsibility: Dmytro Lomaka, Kaltenkirchen.