Yes, thank you for explaining this so clearly. Of course I wouldn't knowingly give physical access of my computer to a malicious hacker, but if my friend asks to use it for 60 seconds while I take care of something else, I'd like to be able to do that without logging out and back in as a guest user. Convenience does matter in these kinds of situations, and deleting these "Show" buttons will make it more difficult for the untrained user to pull a prank or worse.
