I will lock this up since I believe the issue has been solved. If you create a heightmap for one of your maps, there will be a picture shown there in the tiny, black section. If you explore other maps in the game, you will notice that this box will have some sort of landscape image, which can serve as a "mini-map" for the game. The default maps in the game have a picture there because a heightmap was already created for those. Good luck in the game! c: