@nikitonsky this exaggerated example might be surprisingly relevant, since the code might just detect it's being loaded more than once, and skip all the initialization steps on subsequent runs. Embedding several videos into a single page is a common use case, after all.
But I've not tested that, so I can't say for sure.
@iliazeus I can see the time it takes to initialize code _every time you scroll past it_ with my naked eye. That’s definitely a sign of a computer doing crazy amount of work