I'm confused by that thing. After scrolling for a couple of minutes, the animation seems to play on on its own for longer than I cared to wait. Isn't the animation supposed to be coupled to the scrolling?
And it doesn't really feel like scrolling either, since apart from the tiny depth bar on the left, no content scrolls by.
That's a fair point.
The punchlines are there mostly to make the empty scroll a bit more entertaining while you go down. But you're right that nothing really scrolls by in the traditional sense.
The idea is more about measuring how far your thumb travels than about browsing actual content.