Example url: https://codepen.io/wojciechczechowski/pen/jOvEXGP

Steps to reproduce the problem: 
1. Open the link above
2. Click "Open fullscreen" button to call webkitRequestFullscreen() method on the image 
3. Exit fullscreen mode with Escape key

Expected behaviour: 
Image smoothly goes back to it's original position

Actual behaviour: 
Image goes to it's original position, but there's a strange zoom-in glitch at the end of the transition.

Additional notes: 
Seems to happen only when the image originally (before / after entering fullscreen) spans outside the viewport. On images, that fits to viewport it doesn't happen.