These biased diagonal panels, formed by increasing on one side and decreasing on the other, are balanced because they are mirrored side to side on the sock. That makes them diverge at center back and converge at center front. They do, however, have a slightly different row gauge than the vertical stockinette stitch panels, so they need occasional short rows to compensate. Using a subtly contrasting color for those short-row rounds provides a little regular structure to the color variegation.