I was building in my world. Then I left to look around if someone was online. Eventually I entered Pratze’s world. And I saw this:

Those are the same objects I used in my world. And when leaving Pratze’s world and going elsewhere, then returning to his world, those objects are still there. But after a relog, it’s back to normal, or so it seems as of now. But while entering my world and walking around for a bit there, and then entering Pratze’s world again, the same objects are shown. Maybe it’s an AMD bug or I’ve overdid it with the building… I’m not sure if anyone else besides me can see those or not. And oddly, it’s only shown in Pratzes world as far as I can tell.