The Debug Line looks like a square because it is like looking at a line from a plane perpendicular to it, in which case the line gets reduced to a point. It is similar to looking at the x-axis from the origin by orienting ourselves parallel to the yz-plane. In doing so we effectively eliminate a dimension from our 3D perspective and get a 2D perspective or projection of a cuboid (the Debug Line) which happens to be a rectangle or a square here.
1 Like
Liked your explanation… didn’t think about projecting myself into a 3D space with giant axis surrounding me 
1 Like
Hahaha! I’ve been practising some 3D Math, so I’m gonna put the blame on that! 
1 Like