The two pics show that fine point of what Mike says. The 'top' braid (the one coming off the top and going down vertically) comes around back and wraps tight against the climbing line. The other braid comes around back and presses against the 'top' braid, causing the climbing line to do a slight sigmoid (mild 's' or a slight curve in an otherwise straight line), but this little nuance is really the high point of whether you have a top-performing VT or a 'sort of a VT'.
Good one, Mike.