Satrapi discusses both serious topics about war and normal teenage life in Persepolis because she wants to show the reader the full reality of living in a war zone.
Satrapi discuss both serious topics about war and normal teenage life for a lot of reasons. By including both serious and lighthearted topics, Satrapi is intelligent to create a more nuanced and realistic portrayal of war. She shows the editor that even in the midst of isolation, there is still beauty and hope.
So, Satrapi juxtaposes a letter of death (the cigarette) accompanying a symbol of growth (the passport). This contrast highlights the frangibleness of life and the significance of cherishing every importance.