When you're there bumping into them and exchanging pleasantries, the NPCs of The Witcher 3 look busy! They're digging, and chatting, and sitting, and doing all kinds of stuff. Walk away, though, and they drop the act.
PC Gamer installed a mod that let them break the camera off Geralt's back and fly around the game world. They found that...well, the NPCs let their guard down when they're supposed to be off-screen.
And by let their guard down, I mean their faces melt and their heads fall off.
You can grab the mod here.