The icon is supposed to represent one of those waving cat figurines: https://en.wikipedia.org/wiki/Maneki-neko

It has some long tradition placing those visibly on the podium. As the story goes, the idea is that you can immediately see if the video stream freezes up (because the cat in the video suddenly stops waving). You wouldn't immediately catch that in between talks (when you have some time to fix the issue) if the camera was just pointed at an empty stage with no movement. I think at 30C3 or so, I saw one that was placed so that it would repeatedly knock on the microphone as well.

Anyway, the waving cat has become a bit of a meme by itself and mascot of the VOC, hence also the (animated) icon in video player.

Thank you both!