A mental map is a map that is is a representation of an individuals own interpretation of a specific area. This map can be a persons drawing of how they see a particular region or just a map in someones mind. Mental maps are how we organize locations and important land marks using our five senses and spatial recognition.
In this representation of a mental map, this person has drawn there own interpretation of the world. For example, we see the world on a flat surface rather than on its original oval shape. The countries are warped and stretched to fit on the piece of paper. The countries are labeled accordingly but this is by no means an exact representation of the world, but rather one individuals exact perception of what they think the world looks like.