I'm at the window of the prison infirmary. It shows us that he is not only sick but also in prison which is the complication.
Answer: I'm at the window of the prison infirmary.
The first few lines in the excerpt have a cheerful tone. The speaker tells us that he is looking at the trees, and that the road is sunny and leads to the mulberries. However, the speaker then introduces a complication. He is in prison. Moreover, he is in the infirmary, and the only way he can appreciate the beauty of the outside world is through a window.
