As is often said of someones arms or body who practices taiji meaning they are soft but there is a hardness with it,.This would be at odds with the training and ideas one will be working with this taiji style.
The way it’s expressed on this style, the needle (mind) in cotton (body)
the practice helps to make the mind intent like steel or diamond like in focus, the body becomes soft, pliable and resilient like the tall bamboo growing in the forest.