To those who have a peculiar/funny/cryptic nickname: what does it mean?

[Someone]

@Nor_Treblig

Every time I’m gone for a few days you have a new avatar! What’s going on?

I’m here every day and I can say that he is changing his avatar like other people their underwear…

@milanfahrnholz

You tell me, how do even do that when you´re not even there?!

Spies?