The photo shows a Turkish restaurant called "Neden Dürücü" (Why Dürücü). The name is a play on words because "dürücü" means "the one who makes dürüm" (Turkish wrap) in Turkish. So the joke is that the restaurant's name is a rhetorical question asking why someone would want to eat dürüm. The joke is funny because it's a humorous way of making a point about how good the dürüm is at this restaurant, implying that the question is ridiculous because of course people would want to eat their dürüm.