In "The Garden Party," Mansfield's preoccupation with social class becomes a catalyst for exploring the idea of an ambiguous self. She focuses on Laura, a young woman whose self-conception changes as she progresses though a single day and experiences a series of jarring encounters. Mansfield shows that the outer, material world of social interactions has a direct impact on Laura's internal self-conception.
In the morning, Laura conceives of herself as a person who has transcended class differences because of her pleasant interactions with the workers setting up her mother's garden party. She decides, based on these interactions, that class differences don't really exist. Under the glow of this way of thinking, she reacts to the news of the death of a worker by insisting her mother cancel the garden party out of respect for the man, just as she would if a person of their own class died.
The material world then interrupts once again and alters Laura's sense of identity as a person living in solidarity with the lower classes. Her mother bribes her to stop agitating for cancelling the party by giving her a breathtakingly lovely hat to wear to it. As Laura admires herself in it, she embraces the idea of herself as an attractive party-goer. She now accepts her privileged self and drops the idea of class solidarity.
Later, Laura's self-conception changes from one of privileged confidence to one of shame and embarrassment as she brings a basket of leftover pastries to the grieving family of the dead worker. She no longer thinks of herself as either a person who transcends social class or as an attractive and proud young middle-class woman. At this point, she both accepts the huge gap between her own class and the working class, and feels shame over her privilege in the face of suffering.
Key to Mansfield's method is to tie Laura's evolving and ambiguous self-conception to the events going on in her life at any given moment. Laura's changing perceptions of the outside world are what change her self-perception.