What is the stem of the old lady's cheongsam when it opens to her shoulders?

From an online video, when a mother dances in a cheongsam, she pulls the shoulders of the cheongsam away to show her shoulders and dancing movements.

This video triggered a heated discussion among some netizens, and some people found it very interesting. This stalk is mainly a deduction of the word "Lao Niang", and it also reflects people's different views on the integration of traditional and modern culture.