What is Doppelgänger illusion?

The Doppelgänger illusion makes it look like there are two people where there’s only one, like a mirror twin!

Imagine you're sitting at your kitchen table eating cereal, and suddenly, you see another you in the window, but that other you is just looking back at you from the window. It’s like having a twin brother or sister who’s also eating cereal, but they’re not really there, it's just a trick of light and angles.

When you're sitting near a window, your body blocks part of the view outside. The person (or thing) on the other side of the window looks like it's inside the room with you, even though they’re actually outside, just like when you look in the mirror and see yourself, but you’re not really in the mirror.

It feels like someone is watching you or playing a joke, kind of like having a secret twin who only appears sometimes. But really, it's just your body blocking light, making things look like they're in two places at once!