brbo:
«The List of Users option» is actually one I hadn’t thought of, with the original Discussions on this issue. It was found when the original recommendations didn’t work for a user, and we found they were using the “Name and password” option: changing it to the “List of users” option fixed their issue.
As the “Display login window as” options are all about how the Login Window is presented, we see that the first window displayed (except in certain Single-User cases) after a Mac finishes booting up, is called, by Apple, the Login Window (or Login Screen).
In cases where the system is recognized as a Single-User system, if the “Display login window as” is set to “List of Users”, the Login Window (or Login Screen) is skipped, to show the Lock Screen (or Lock Window) of that Singer-User.
Otherwise, the Login Window (or Login Screen) is always displayed right after the system boots up.
Unfortunately, none of us have found a way to change the background of the Login Window (also known as Login Screen).