"In addition to using measuring tape, one has got to assess the posture of the body with one's eyes" --because while you can measure the length and size, one must rely on observation for the different body postures.
楊成貴也進一步指出：「量身除了用尺之外，還得用眼睛觀察體型。」因為長短大小可以量得出來，不同的體態就得靠觀察。