The reason why Shelley writes this account of the origin of her story is that she can control the narration.
This refers to the storytelling that is used to show a sequence of events and how they affect the plot of the story.
Hence, we can see that what this contradiction tells us about their personality of Shelley is that she is a person who wants to tell the truth and does not want to be misunderstood.
Read more about narration here:
https://brainly.com/question/7980953