[Katsumi too looks around, and sees no sight of any sort of camera equipment for whatever occasion he assumed he was interrupting.]

Huh. So, you're just cosplaying for fun then? ...Not that I'm judging, by the way. [Not to be rude or anything.] I thought there's some kind of event going on if you're dressed up like that.

[Like, that's an outfit you get to see in fashion subculture magazines and online circles. So it's rather bold of Vanitas to show off his threads with the fish as his spectators. ...If they're even watching at all.]