Trillian ✅✝️ 🇬🇧👍 on Nostr: This "illusion" is all over the Net this morning - I saw it in the newspaper, asking ...

This "illusion" is all over the Net this morning - I saw it in the newspaper, asking "how many blocks do you see?"
But I cannot understand how some people see three blocks. To my mind there are definitely four, especially if you look at the ends.
But does anyone really see three? If so, how?