The external setting in the story is the trip to China and this is an elemental theme in the book. The narrator has not been raised in China and never had been able to relate to the Chinese way of life or felt Chinese.
The narrator's journey in the chapter takes her to a place she had never been before and her journey is inward as well as external. As she sees the relationships and the style of life, she is able to have a look at the way her mother and father had been raised and why they thought and felt different than she did when she was growing up.
Being able to witness the customs and the Chinese experience for her enables her to better relate to things her mother had said to her as she was growing up. She is able to begin to build a connection to her heritage.