Created attachment 6477 screenshot Now that we're not actually using a screensaver, but light-locker so the screen can be set to blank, sleep or switch off, perhaps the label in the Auto lock session of the security tab could be reworded. Never When light locker is activated When light locker is deactivated (Managed to work out what to change and where locally to see how it would appear - see screenshot)
Created attachment 6478 screenshot
Not sure that'll make things really clearer. Thing is, we *are* using a screensaver, it's just not an animated one, it's a blank screen. And that blank screen comes for X11 itself and light-locker listens to the signal and then waits for n seconds (option below the one you mention) and then locks (which means switching to a new VT). The automatic locking can happen before or after the screensaver kicks in. If it kicks in *before*, that's more secure, but might cause trouble with suspending by closing the laptop lid. If you lock later, suspending works. I know this is a bit complex and we likely shouldn't expose this to the user at all, however it seemed like the best solution for the rather difficult "black screens suspend issue" xubuntu 14.04 was haunted by.
You understand that, I understand that. However, the person just using it might not (and in at least one instance didn't) Sean mentioned he wanted us to be looking for usability bugs etc This is one :) Most people when asked what a screensaver is wouldn't come up with a blank screen from X11 - they'd be expecting something like xscreensaver. That said - I'm not too bothered if nothing changes - I've done my bit (and learnt something in the progress)
What's more, this setting *can* trigger an actual screensaver too if installed... Plus lightlocker is kinda deprecated these days over xfce4-screensaver.