When on the Duplicant selection screen during a new game creation, screenshot mode can be turned on.
This is very disturbing if you do that by mistake, and are stuck there not knowing why you landed there and how to get back (the text at the bottom left explaining how to go back is small, not very visible and you probably won't notice it before it disappears).
Screenshot mode should be disabled when you are on that screen.
Start a new game, select a seed.
When you are in the Duplicant selection screen, use the Alt+S shortcut to land in screenshot mode.