In my opinion, it is about the third decision, when making a map.
First decision is: What Place do I map? Is it a building floorplan, is it a town, is it a whole planet ... ?
Second decision: What is the topic of the map? Is it political. topographic, geologic, technical, tactical ... ?
Third decision: What style will the map have - is it a modern map or a fantasy-historic map ... ?
So I do not 'know' what style a map should get, I 'decide' ...