How does the author illustrate class distinctions in the novel, What We Were Promised?

The two different sets of elevators at Lanson Suites—one for staff and one for residents—symbolizes the class distinction in Shanghai and the physical segregation between the staff and residents. At Lanson Suites, the maids and other staff travel up in service elevators. Meanwhile, the residents travel in their own elevators, with padded quilts covering the walls, a framed mirror, and a little marble shelf displaying a vase of red and coral begonias. When Sunny becomes an ayi, she starts to travel in the resident elevators, which indicates how she now occupies a place somewhere in the middle, yet still subservient to the family she works for.