A key theme of this excellent short story is that of class, and the way that Laura begins the story at least by trying to ignore class and pretending that it does not impact her. An important part of the beginning of the story is when she watches the workmen construct the marquee and Laura comments on how nice the workmen are and how they compare much more favourably to "the silly boys" with whom she dances from her own class. Note what she thinks:
It's all the fault, she decided, as the tall fellow drew something on the back of an envelope. something that was to be looped up or left to hang, of these absurd class distinctions. Well, for her part, she didn't feel them. Not a bit, not an atom...
She even goes as far to imagine that she is a "work-girl" as she watches the men do their work. Of course, this feeling of companionship with the working class brings Laura into her conflict when she feels that the garden party must be cancelled because of the death of Mr. Scott, a working class man living very close to the garden. When she goes to her sister Jose and then to her mother, she is met with the inescapable reality of the way that class does matter and that it cannot be dreamed away. Consider how her mother responds to her:
"You are being very absurd, Laura," she said coldly. "People like that don't expect sacrifices from us. And it's not very sympathetic to spoil everybody's enjoyment as you're doing now."
Class is therefore a force that initially Laura tries to resist, but in the end is forced to acknowledge and respond to.