From what I’d expect, the lines coming out of the other lines can not, and will not, be able to make a perfect cube. Said “other” lines are titled a little to the left or right, your eyes are not able to create that feeling of how the lines are designed. As geometry magician Wikipedia says, “parallel lines are lines in a plane which do not meet; that is; two straight lines in a plane that do not intersect (and, colloquially, lines that keep a fixed distance between each other) are said to be parallel.” TL; DR, they are not parallel at all.
