The key to understanding this is to see that the character of Maud herself is a metaphor for the male presumption of entitlement over women. She is taken by her Uncle from an environment where she is happy into his house, in order that he might use her eyes and hands to substitute for his own failing faculties in secretarial work on his pornography collection. He is thus objectifying her through his power over her in a similar manner to the way the male gaze objectifies women through pornography.
Her Uncle cares nothing for her happiness in this new role and is oblivious to her own independent inner life. Likewise, he treats the erotic stories in his collection in a similarly detached manner, seeing them only as academic curios. This typifies the male response to both pornography and women as something functional, with no independent or emotional value.
As she comes to understand what is in his collection, she begins to learn about the world of sex through the books purely to facilitate her Uncle's desires. Thus her own sexuality is subjugated to the needs of a man, as women's sexualities often are.
As the plot progresses, however, Maud begins to rebel both against her Uncle and against male power over women generally. Her final act in escaping her Uncle is to destroy part of his collection, again a metaphor for the sexual liberation away from men that she has found with Sue. Indeed as the plot unfolds further, both protagonists begin to assert themselves against the dominance of men in their society.
It is significant that at the close of the novel, it is implied that the protagonists are going to earn their livelihood making pornography of their own. It will be a different kind of pornography to that in Maud's Uncle's collection, however, one created by and for women. One with subtlety and emotional resonance. It is noteworthy that in the passage of her work that Maud reads out:
Quickly my daring hand seized her most secret treasure, regardless of her soft complaints, which my burning kisses reduced to mere murmurs, while my fingers penetrated into the covered way of love
She uses the word "love" to indicate the tone is not one of sex but of erotic love.
The book is thus subtly railing against the typical male-dominated, objectifying form of pornography, which rules the lives of both protagonists and which they jointly reject. However, it opens up the possibility that a more female-oriented pornography can be a disruptive power for positive change in a male-dominated world, helping women to discover their own sexual individuality as opposed to being mere tools for the pleasure of men.
References:
- Sarah Waters’s Fingersmith: Leaving Women’s Fingerprints on Victorian Pornography, K.A. Miller, Nineteenth-Century Gender Studies, Issue 4.1 (Spring 2008).