Independently change Lock Screen and Login Screen background image in macOS Mojave First of all, this question requires some terminology.


I'll refer to the Lock Screen as the screen you see when you lock the screen.
I'll refer to the Login Screen as the screen you see after a restart before you login.


This answer gives a great method for changing the Login Screen background image. I've found other sources that give the same answer. However I've not found any way to change the Lock Screen background image to be something different from the Desktop's background image. Is there a way to do that?

Furthermore, when I choose Logout [user], I see what I have called the Lock Screen, not the Login Screen as I would expect. Is this the intended behavior?
Mojave will use the desktop image from your first desktop on the lock screen.

The easiest way to change the lock screen to something else is to add a desktop, and drag it to be the first desktop and change it to what you want the lock screen to be.