Do you recognize people on here by their pic or their username?

I recognize them by their foul stench

Pic usually..and then they change it and I get confused

I've selected the user, but sometimes I can't tell unless I see their bio.

Username.
Which is why it's so irritating when folk change them.

It depends on which part of my brain is freshest. 🤪 (both)

Some its easier to remember their name, others their pic..

A combination is the safest bet.

Name

A combination of both, usually, unless the name is unique.