I have always "believed in the box" for matters related to the shape of the realm, but lately I've noticed the coordinate system for "Realm 1" (No Man's Land and the 4 main lands) does not picture the map the same way as the box does.
From the box's perspective, you'd have 3 (or 2, depending on how you look at it) sets of rectangles forming "Realm 1". That can be seen from the picture Burns posted.
On the other hand, the map coordinates form a 10x9 rectangle in which all Realm 1 is included (Curiosity: Realm 1 has exactly the same grid size as the Labyrinth. Mods, if that's considered a spoiler, please remove it).
My brain's been more inclined to believe in the coordinates rather than the box, but judging from this announcement, it seems the box might show the right shape. Perhaps the coordinates system do not take scene size into account. If it did, the Loreroot section could indeed be bigger and deform a part of the rectangle, making the coordinate-based map resemble the box picture. Does that make sense? But then again, if that indeed happens, it would ruin the "coincidence" of Realm 1 being the same size as the Labyrinth.
Edit: Replaced "cube" by "box" thanks to a smart friend that pointed that out for me.
~Aelis