How does this sentence affect the story?He spent hours each day before first one mirror and then another; and he did not notice that the windows were growing narrower and the mirrors wider. How does this sentence affect the story?

This sentence shows how the palace will become a prison in the next events of the narrative.

Explanation:

This question is about "The Magic Prison".

In writing the sentence shown in the question above, the author used a technique called "foreshadowing". This technique allows the author to forward information about things that happened in the next events of the narrative. In the sentence shown in the question, we can see that there is a change in the structure of the castle, this change may be something only psychological, but it awakens a sense of imprisonment and claustrophobia, which allows the reader to understand that the castle will become a prison .

The answer would be, a friend avoiding a controversial topic