A family photo (symbol)
A family photo is a symbol of a dream, a goal, the most desirable thing for Sean and Roza. To Finn, the photo looks “like every other photo of every other family: two parents, two little kids, all the people smiling like nothing could ever go wrong”. But Roza does seem “to see something in the picture”. When she gives it back to Sean and he grasps the edge of it, she doesn’t let go “for a moment, both of them holding on”. This symbolizes their shared views on a life and its purpose. Both of them are family people, who would be absolutely happy to be those people in the picture. They want to have a family, two little kids, all of them smiling and they would do everything possible to prevent this shared happiness from breaking.
The beast (allegory)
The beast that “had prevented Roza from escaping” is an allegory of her fear of the Scare Crow. It looks like “the largest, the ugliest, most miserable dog” but Roza manages to tame her fear and turn this wretched beast into her friend. Later on, the dog becomes Roza’s friend and there is nothing to prevent her from planning her escape from the Scare Crow.
Learn to trust (Motif)
It is not an easy thing to trust others, but sometimes it is necessary to do so. If Sean would trust Finn to help him or trust Roza enough to believe that she loves him too, his life would be easier. If Petey would stop questioning herself whether she has a reason “to trust Finn” or not, she would be much happier. As soon as the characters of the novel stop questioning the intentions of their loved ones every time, they learn how to trust and achieve happiness.
