The photo shows a wall with graffiti in Turkish. The graffiti says: "Dünya yuvarlak, insan bi köşeye çekilemiyor." The joke is a play on words. "Yuvarlak" (round) refers to the shape of the Earth, but it also sounds like "yuvarlak" (round in a way that can roll), making it seem like humans are trying to roll into a corner. It's a humorous observation about the impossibility of escaping the world's problems.