I don't agree with the common complaint that transitions and animations are just aesthetic fluff. Done right, they give the user additional feedback as to what'

I don't agree with the common complaint that transitions and animations are just aesthetic fluff. Done right, they give the user additional feedback as to what's going on, e.g. in the example announcement, zooming in on one particular video making it full-screen. This might be less relevant to power users, but imagine someone accidentally clicking somewhere and suddenly facing a full-screen video. With the transition, it's at least clear what action is happening. It's similar to buttons indicating their state (hovered, pressed, clicked). The main reason animations can get annoying is that people don't get the timing right (too slow), or really just use them to show off. Some even use transitions to gloss over the slowness of their system, which is infuriating.