If you're sitting on the opposite side of a table looking at a map that a person on the other side laid out in front of them, you don't just see the map from the other side? You instead see details about volume, shape, distance between points, geometric similarity, colour, and so on? I sincerely just see the same map even if I'm across the table, except flipped. I'm not sure how it would impact my drawing a map, though that isn't really what the article talks about.

Can you read upside-down or does it become a jumble of lines? I can read upside-down with no special effort so maybe this is canceling something out.