I exited the End after I had slayed the dragon. When I was in the Overworld, there was still the End stone and obsidian pillars and all the End terrain in the Overworld. It still had the normal sky with the sun and clouds, but the landscape was exactly like it was when I was in the End, not the Overworld. I wanted to screenshot it, but I had already deleted my world to make sure no-one was hacking.