Exactly. Maps are free. Joke maps are also free. So instead of paying money, and somebody taking that money and assuring you this is the right thing. You get a free map, that might be a joke, but you don't know it's a joke cuz you don't know the map. And we get some funnies
Have you ever tried drawing a map from memory? It's interesting, what you do and don't remember and why. That's why this is funny - what's salient to the other person and what's not. No American would want Florida to be bigger, for instance.