The "uncanny valley" effect is a psychological phenomenon, where if you take objects that look more and more humanlike in their features (starting from something that doesn't resemble a human at all), using elements that are generally deemed as "cute" and pleasant to look at, there's a strange point at which the thing becomes highly disconcerting and repulsive. So a teddy bear may look cute, a doll resembling a small child may look even cuter... but the more "realistic" human features you keep adding to it, at some point, when it's getting closer and closer to looking indistinguishable from a human, it becomes really disconcerting. It just looks like there's something wrong. What was something cute and huggable suddenly becomes something that causes more or less a phobia.
I have noticed, however, that there are some other things which are unrelated to that, but still may cause a sensation that's similar, and I'm wondering if the psychology behind it is the same.
For example, if you put a body harness on somebody and attach a camera onto that harness pointing at the person's face, the resulting video looks mostly ok, and there's nothing too bothering about it. It looks relatively natural and normal.
However, put a helmet on the person and attach the camera to the helmet, pointing at the person's face (from any direction), and the resulting video suddenly becomes really awkward to watch, at least for me. When suddenly the face stays completely stationary on the video while everything else moves, it looks really unnatural and disconcerting. It doesn't look normal, and it's quite bothering to watch.
(I noticed this when some "reality TV" shows have done exactly that. The result is really awkward.)
I'm wondering if the psychology behind this is similar, or even the same, as behind the uncanny valley effect.