FWIW, I do think the FB avatars are being used as part of a virtual gathering app (lol, what is this the 90s?) called Horizen or something. Since we gotta social distance and they’re trying to double down on all this “social” aspects of social media.
That said, you 100% hit the nail on the head. I had a custom avatar made by an artist I comissioned, and immediately I was like “my chin is huge in this, i look like jay leno”, obviously not to their face but still in my head I just pretended to be happy cuz I didn’t want to demand someone go back and try again. I’m paying for their interpretation of me and it may not fit the interpretation I have in my head.
Which, I think is another thing, when you make an avatar of yourself, whether in an app or a game or whatever, you’re making an “ideal” version of yourself. So maybe you have cooler clothes, cool hair colors or different eye color, etc. You can feel more comfortable being vain.