This also happened to my friends switch, on MCPE-54627
You may need more evidence, such as using the character creator in a video, as you could easily make this photo if you downloaded a backwards skin.
Was it in your world, or in another players world? This has happened to me before, when i was making a minecraft map. this can happen when the world has been edited by a third party software (such as McEdit, or UME).
I am pretty sure that is to do with your device, not the game itself. your device may have lag when trying to handle the game and may be skipping frames to catch up with where it should be at. I may be wrong but that is what i see from the video evidence.
this is the same as my post, MCPE-54627