Mansfield's main theme in "The Doll's House" is the injustices and cruelty associated with class distinctions. Set in colonial New Zealand, Mansfield shows that differences set along class lines are rigidly adhered to. She also shows that those in a higher class take an almost perverse pleasure in being cruel to those of lower classes.
Along with these ideas, Mansfield does show that there is some hope because the classes are forced to deal with each other in everyday situations. This is shown through the character of Kezia and the lamp.
The central theme in Katherine Mansfield's short story "The Doll's House" concerns the inhumanity of social class discrimination and the hope for the dawn of a new day bringing true equality.
Mansfield grew up in British colonial New Zealand, and her short story, as well as many of her other works, reflect her own experiences and observations. In colonial New Zealand, not many schools existed; therefore, the rich were forced to attend school with the poor working-class children, a truth reflected in the setting of "The Doll's House." The three Burnell girls, who are given the dollhouse, represent the rich who must attend school with the "judge's little girls, the doctor's daughters, the store-keeper's children, [and] the milkman's." But this mix of society, rather than creating equality, only serves to emphasize established social hierarchy. The Burnells especially emphasize social hierarchy because, being rich, they look down their noses at others in their school. Though they socialize with those whom they are allowed to at their school, they only deign to do so. Isabel, in particular, only socializes with other girls when she knows doing so will make them envious of her. The dollhouse they are given symbolizes their view, especially their parents' view, of ideal upper class life, and evidence that the Burnells only deign to socialize with those beneath them at their school is seen in the fact that the Burnell sisters are granted permission to invite girls from school to come see the dollhouse, two at a time, but the girls are given strict orders about what their invited guests are permitted to do:
[The invited girls were not] to stay to tea, of course, or to come traipsing through the house. But just to stand quietly in the courtyard while Isabel pointed out the beauties, and Lottie and Kezia looked please.
While the Burnells look down their noses at those they deign to socialize with at school, they, along with the rest of the school, completely snub the two Kelvey girls, who represent the poorest of the poor. They are daughters of the washerwoman, and their missing father is rumored to be imprisoned. Being the poorest of the poor, they are completely forbidden to come look at the dollhouse or even to so much as speak to the Burnells.
Yet, while the dollhouse represents the ideal upper class life, it contains one more symbol, the lamp that looks so real that Kezia, the youngest, thinks it is the best part about the dollhouse. The lamp symbolizes a ray of hope in the dark world, of hope for the elimination of socioeconomic disparities and the creation of true equality. We particularly see the symbolism of the lamp when, Kezia, against her family's wishes, invites the Kelvey girls in to see the doll house. They are soon chased away by Kezia's aunt; regardless, Else Kelvey, the youngest, speaks of seeing a glimmer of hope for a better tomorrow when, at the end of the story, she smiles and softly says, "I seen the little lamp."