He's clearly in shock.

Sometimes the biggest surprise is the one staring back. In the United States, a cat pads up to a mirror and locks eyes with its own image. It pauses, studying the face on the other side, as if trying ...

Have you ever heard of the 'cat mirror theory'? It's the idea that when cats see their reflections in a mirror that they don't recognize themselves and instead think they're looking at another cat.