Actually neither of the above. I'll most likely say "Who is this person?" when I followed them for a comic series, or some other art series (like for example series of pokemon drawn in some specific style) and when they upload something not related to the said series.
I hope you understand this, it was really hard to explain xD
For me It's strange that the most people answered the username, because I think It's more confused when somebody change its style. For my part It's rare that I memorize the name of most people whom I watched, I only memorize them for they style (or they icon.. ), because I usually watched people because of I liked them style what mostly caught me.
well it depends; if their style has changed drastically -- for a random example, realistic to manga -- I'd be rather confused before noticing who it is also I have 1,000,001 characters so I wouldn't blame anyone for creating/changing a new one so I guess username?? icon really doesn't bother me because if I get too curious I can always hover and see what their username is
Well the username is what we know people by on here. And the icon is kinda like their face. If someone in real life changed their name then I wouldn't know who they are if someone talks about them using that new name. If I met them and had to use that new name it'd also be really confusing. Same with the face, it's the main thing that identifies who we are. Change that and I'd be talking to a stranger until I find out who they are.
Icons can get me messed up for a few moments, as I usually look at those so see who posted/answered things first, but then I quickly realize who it is again. When it's someone who I don't talk to a lot (so I wouldn't recognize their icon as readily) and then they change their username it throws me off sO MUCH OH MY GOD It's actually happened twice in the past week and both times I had to look at their gallery to remember who it was. xD
I can keep track of when my friends do it, most of the time, but when other artists change their username, (especially if they do it often, and change it to something completely different) I sometimes just don't remember who they are. xD
Icons, characters and drawingstyle do help me recognize the artist, too but changing those isn't as confusing as the username, in my opinion.
Well I think all of the above can be sort of confusing for me. Not so much the icon one though, unless it isn't one of their characters. I usually have the most problems with people changing their usernames.