I'm surprised you noticed! I think you may be the first I've seen. Most people just think it's a 1 vs 2 column layout; but we didn't find that quite satisfactory...

If you guys like cat optical illusions, they're susceptible to a few others as well, like the rotating-snake one: https://gwern.net/doc/cat/psychology/index#regaiolli-et-al-2... https://gwern.net/doc/cat/psychology/index#szenczi-et-al-201...