the first picture is called the baseTiles, it is a simple, black & white & ocean/blue colored map (only 3 colors, or you will have issues). Also, it can't have any anti-aliasing (fuzzy borders) or else you will have issues with the map maker.
The purpose of this map is to use the map maker on it, to tell the map maker the territories, borders, etc.
the second picture is called the reliefTiles, and it is supposed to be what the map is going actually look like. it should be good looking, beautiful, and can have all the art and colors you want. it gets displayed on TOP of baseTiles, and is usually transparent enough to let the territory ownership colors show through.