@codinghorror hit the main benefits pretty well
I’m all in on rounded avatars and agree with some other voices here: it’s all or nothing; adding more inconsistency to the core is a bad idea. Overall I think the pros outweigh the cons (are there any non-subjective cons other than cutting off image corners?)
There’s also a bit of scientific data to back it up (though, this type of stuff can be debated infinitely)
How’s this for a quote:
perceived salience of a corner varies linearly with the angle of the corner. Sharp angles generated stronger illusory salience than shallow angles
As the article I linked clarified: hard corners stand out more. Avatars are important; buttons are important-er. So I think creating the contrast between the two is worth it.
As mentioned, most avatars are faces of some kind… this is an eye-tracking example done on an advertisement, but it’s generally known that humans prioritize the face versus whatever is around the face. I don’t think we’d be losing much by ditching corners!
You’ll also find people who will speculate that image squareness is dictated by technology constraints (ease of film and screen manufacturing) and naturally our field of vision is round-ish anyway… but then we can start getting really philosophical and what can be more bikesheddy than that? 