The picture for this blog entry allows the comparison of strong Yin development to less strong Yin development.
The ability to open the mouth very wide and to extend the arm straight out are both signs of strong Yin development. The man who is second from the left in the picture has a very wide open mouth,
and his arm is extended straight out.
Compare the man’s mostly extended straight out left arm with the other men’s arms that are bent at the elbow.
then compare the amount his mouth is open to the amount the mouth’s of the other men are open.
If you believe you see other men with very wide open mouths, before you decide they have the same amount of mouth opening as the man who is second from the left, compare the look of their head to the look of the head of the man second from the left.
There are major differences to see if you are diligent in your examination.