We use a startup script on the mac to give users a choice of Windows or Mac. When one chooses Windows, the VM launches and Windows appears. We have a small bug recurring wherein the VM occasionally hides (as if in another space) and a user has to click on Fusion's icon in the dock to "slide" the VM back into view. Strange as this is, it's not the subject of this question. Instead of finding and fixing the root cause (long, long story), I have the script change the Mac's desktop picture to one with an arrow pointing at the Fusion icon in the dock with a note "click here to get back to Windows".
The question:
If automator script has the VM start up then change the desktop picture, the desktop doesn't change. It changes the picture only if it done first, leading to some confusion for the user. Is Fusion somehow blocking this sys pref change on the mac? The VM runs full screen, if that helps.