Doppelganger
When we say “doppelganger”, we usually mean someone that bears an uncanny physical resemblance to another person. The original concept of a doppelganger has a more supernatural connotation, though- the illogical phenomenon of one person appearing in two places at once, or your own ghost appearing to you while you are still alive. Such an experience is an unseemly portent, and maybe an omen that you will soon die. In the case of these kitties it might be a self-fulfilling prophesy.
Maybe because I spend a lot of time looking at strangers’ cats (much more time than I spend looking at strangers’ faces) it’s not unusual that I come across cats that look very much like my own, and for the briefest moment wonder how someone else is posting a picture of my cat on instagram from across the globe. There is something satisfying about finding these familiar faces and for an instant, being fooled.