[fladd]

What exactly does this do? They have examples with a divider in the middle that you can move around and one side says "input" and the other "output". However, no matter where I move the slider, both sides look identical to me. What should I be focusing on exactly to see a difference?

[7734128]

It has clearly just loaded incorrectly for you (or you need glasses desperately). The effect is significant.

[fladd]

Tried again, same result. This is what I get: https://imgur.com/CvqjIhy

(And I already have glasses, thank you).

[7734128]

That's an error in your browser. It's not supposed to look like that.