I personally think the whole slider comparison method is pretty dumb - it makes direct comparison of certain image areas much harder (since you have to swivel your mouse around, not to mention how annoying this is on mobile) compared to a simpler solution where the whole image changes on mouse hover (which on mobile works nicely with a tap). This is how basically all screenshot comparison sites out there operate, and it really does work the best for the purpose of comparing two images like this.
Is it actually an animation? I assumed it was lag caused by redrawing each time the mouse moves and not ignoring queued mouse movements. Perhaps I assumed incorrectly.
I thought the BPG page earlier had a much more instant response, but it appears I remembered incorrectly because it behaves almost the same. My bad. http://xooyoozoo.github.io/yolo-octo-bugfixes/
