I am just sharing here another way of deploying silently a new Desktop Background to Mac computers without using Script install, Desktoppr or a Configuration Profile. This workflow is compatible from Catalina to Monterey Beta.
Create your Jamf Policy to deploy it
#!/bin/bash open /Users/Shared/Your_Automator.app sleep 10 rm -R /Users/Shared/Your_Automator.app rm -rf /Users/Shared/Your_Image.png
Hope it may be useful!