The kingdom
This princess belongs to a specific kind of government imagery. She is part of the façade of power which makes her part of the social fabric. She is a public figure and the town pays attention to her with scrutiny. The town is part of this imagery as a check and balance against the royal family, but they are capricious. Often, the political landscape is complex, and Eadlyn realizes that part of the way she fits into this imagery is as a figurehead for public attention, which she doesn't want, but has to accept.
Competition and romance
The Selection turns the normal process of romance into something more hyper-competitive and public than it would normally be. This highlights the competitive elements of romance which are present in normal life, but which are blown out of proportion for this public entertainment. Eadlyn is subject to inflated egos, overly competitive men, and the jealousy that comes from the Selection process. This is her sacrifice for the order of the town though, since it is genuinely interesting to the people.
Family imagery
Eadlyn often struggles to see the point of romance and mating. She doesn't really want to subject herself to a marriage, nor does she enjoy the process of comparing and judging between suitors. Often she finds herself at her wits' end, especially toward the end of the novel when she goes to vent to her mother and finds the answer to her question in a painful imagery: her mother has had a heart attack. In light of this, she reassesses the family around her. She sees their sacrifices and becomes more willing to sacrifice for the continuation of the family.
Power dynamics
Eadlyn is part of the power in her town, but that doesn't mean she is free. Rather, she is subject to the dances of power dynamics. These dynamics make it hard for her to deviate from public expectation, especially because the political life of the kingdom is still pretty unstable after the riots from the previous novel. She learns to become more powerful by succeeding in her life and by accepting responsibility over the arenas in which she feels disenfranchised.
