Picture by a username (6)

I believe the answer is:

avatar

(Other definitions for avatar that I've seen before include "Internet ID icon" , "Person who embodies a particular ideal" , "Blockbuster film" , "Divine incarnation" , "Cyberspace person's image" .)

I've seen this clue in the Universal.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.