To have confidence, I'd want a locked/disabled state, while whatever action is processing. The jiggle gives me an uneasy/broken feeling, as a button, even though it is very satisfying as a whimsical object.

It reminds me of the hockey puck buttons that you record a sound on, and how if you press it too quickly, the sound can't keep up, and it feels janky.

Hopefully this isn't too negative, because the tutorial was very readable, informative, and engaging, even for a css novice who had no intention of studying css today.