I think this is pretty misguided. If a person want’s to change it, fine. But the major difficulty is the fact that if they do not, the little circles look the same. Hard to differentiate between the too. To the point of profile picture being personal, this would be in the work setting. This is not facebook/instagram. It is a work scheduling thing.
To be fair we are experimenting with Asana. There are a lot of competing products out there. I do see this as a weakness of Asana. Seems like it would be trivial to change to implement.
I understand “you can use whatever software you wish” that is true. We very well may. Again, testing the waters. I’d suggest you implement this change.