My sister found this bug several months ago. This is what she said about it:

"When I look up, it looks down, and vice versa. I tried deleting the app and re-installing it, but the glitch continues to happen."

I think the reason it is not happening to me is because I think mine is a 4th generation and hers is a 3rd generation. I can confirm this is happening because I have seen it at least once. I cannot give you screenshots because it is not my device. My sister is very annoyed by this and doesn't play MCPE often for that reason. I have not experienced this glitch but I can 100% confirm this happens.