Her father went back behind the gray sour velvet curtain that divided the store into two parts, the larger public part in front and behind a small dusty private part.
 

This quote describes the jewelry store Mr. Addams works in, during Part Two, Chapter 1, when Frankie visits him and learns about Uncle Charles's death. The novella is filled with descriptions of dividing lines, of rifts between people, of split personalities, or the like. All of these serve as metaphors for the fact that there is a chasm between Frankie and the rest of the world. Other examples are the fact that Big Mama describes Honey as someone God never finished and Frankie imagines him as someone with only half a body. When McCullers writes that Frankie feels "double-minded" about Saturday evening, it suggests she is indecisive.

The duality described in this quote represents several things. It signifies the shift between adulthood and childhood. Frankie is in a kind of limbo between the two points. She sits on the dividing line itself between the two points. And the duality speaks to the difference between the public and private selves, as well as the conscious and unconscious. Frankie changes her name to F. Jasmine to create the surface impression of childhood. However, we know that inside she is still a child, creating wild illogical fantasies that will inevitably disappoint her. She is someone who has very little access to her unconscious motivations or instinctual fears. So it is our job as readers to take away that dividing line, that gray curtain, which hides her true feelings. That way, we can fully interpret her character for ourselves.