Game Help: I see me!

So while trying to trade with someone I noticed in my Festival Plaza that I can see and talk to myself. Dressed in the same clothes and everything as how I had it set up as if someone else was talking to me. I have 2 3DS's and the other one wasn't on at the time. I had this happen in both Sun and Ultra Moon and this was after I had to do a system update on my 3DS.

Did you test as to whether you were able to trade and/or battle with yourself?

That I didn't do...I just know I could talk to myself as if it were someone else doing it.