Here's the problem: the narrator, an educated and sophisticated man, is speaking on behalf of an ignorant and almost voiceless woman. How can we be sure that he's speaking accurately? Welcome, friends, to one of The Hour of the Star's main concerns. The narrator clearly has immense control over his language, and yet he can hardly tell the story because of his ethical and literary concerns about how to tell it. It's almost as if language is preventing rather than helping communication.
Even though Rodrigo claims to be a masterful writer who aims to write simply, written and verbal communication fails at many points in the story.
While Rodrigo uses the second person to delve into the philosophical and the challenges of writing, he's not actually speaking to us, but to himself.