https://www.youtube.com/watch?v=D61LxZPW0S0&t=1s
Old photo,old master :Tai chi Ji(挤) and An(按)of Yang Chengfu (从杨澄甫前辈拳照,深悟太极八法:挤和按)
Takes a lot of thought to convey concepts expressed in different language
Interesting point of understanding "where is center" when viewing old photos of past masters...