Complex sentence: The "C'" and "Y" axes now point to the midpoints of the edges of the box, but the magnitude of the reference frame has not changed (i.e., the sphere did not grow or shrink).
Split into simpler sentences: The "C'" and "Y" axes now point to the edges of the box, but the magnitude has not changed. Also, notice that the magnitude has not changed (i.e., the sphere did not grow or shrink).