If you stand still and look around with the mouse or a controller's right stick, your avatar will jitter in place. The effect is much more noticeable when holding an item, because you can see the arm rapidly flicking side to side.

This also extends to movement, specifically running. Turning while walking will jitter the avatar, and turning while running will jitter both the avatar and sometimes your view, making it look like the game is lagging. I'm running at a stable 59-60 framerate.

Tested in multiple worlds and avatars.