The silkworm room's significance is based on the way that it provides a connection between the modern day prostitution of the geishas and the way that women were prostituted in other ways in the past. Let us remember that Shimamura visits the villages where the costly cloth chijimi was manufactured in the past. The description of the cloth is interesting in the way that it can be related to the way in which Shimamura thinks of the various women in his life and how he romanticises them:
The thread was spun in the snow, and the cloth woven in the snow, washed in the snow, and bleached in the snow.
Shimamura is a collector of this priceless cloth, but it is only after visiting the villages where the cloth was made that he recognises the cloth was only produced as a result of exploitation of young women who were weavers. He remembers that Yoko originates from this kind of village and he reflects that if she had been born in an earlier time, she could have been one of those exploited girls, just as both she and Komako are exploited in today's day and age but for a different reason. The timing of this realisation combined with the incident in the silkworm room consolidates the novel's theme of exploitation of women which is shown to be timeless and the result of men who romanticise, just like Shimamura himself has done with both the cloth and Yoko and Komako.