Picture next to a username (6)
I believe the answer is:
avatar
'picture next to a username' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for avatar that I've seen before include "Screen icon" , "Blockbuster film" , "Descent to earth of deity in human or animal form" , "Manifestation of person or idea" , "Online image" .)