Follow-up from "ScreenChooserDialog: make it obvious that they're checkable"
The following discussion from !59 (merged) should be addressed:
If there's only one item in the list, does it even make sense to show a list at all? In that case, it isn't a "pick which thing to share" dialog, but rather a "confirm sharing the one thing that's sharable" dialog. Could we maybe hide the list and replace it with a big honkin' "yes share my screen lol" button?
If we are thinking about design, we could also consider including the "share an extra virtual screen" which is already implemented in kwin and we could implement here with "minimum effort". Question is whether we need/want that and how it would be presented.