This passage describes Martin’s reaction to the first time that Caitlin includes a photo of herself in a letter she sends to him. Caitlin includes the photo perhaps because she believes that showing what she looks like is the best way to reveal her true self and signal that she is looking to form a deeper relationship that goes beyond a school-sponsored assignment. Martin is eager to reciprocate, but the problem is that Caitlin has asked him for a photograph in return, and photos are hard to acquire in Zimbabwe. Photos are something that Caitlin takes for granted and slips…