Island imagery
The imagery of the island does two important things, among others. The first is to provide a proximity to water that allows the plot to involve a conversation between water and land that is an imagery all its own. The second abstract quality of this imagery is that the island acts as a kind of domain to itself. That natural isolation makes the novel into an uncanny thought experiment. In island stories, the narrative is very often a commentary about human nature in a vacuum. This use of imagery is similar to that in novels like Lord of the Flies.
Human and animal imagery
The novel blends water-mammal imagery with human imagery which makes the reader consider a perplexing abstract implication. What is the difference between the seals and the humans? By stating in the prose that seals were able to shed their skin and reveal competent human beings underneath, the reader is invited into symbolic considerations. Perhaps the reader says, "This makes no sense," but then again, how different is this strange, fantastical imagery from the reality of human evolution? The scientific consensus is that humans did literally emerge from water-dwelling life forms, but through evolution. For another taste of this kind of absurd animal-human imagery, watch the movie Arctic Heart or consider the world myths about mermaids.
Embarrassment and shame
The novel can be basically summarized as a novel about using shame properly. The town gives a life to Missakaela which is absolutely riddled by embarrassment and humiliation. That emotional imagery is shameful because it refers the reader to a feeling of worthlessness and rejection. Is that fair? The novel answers that question through an unpredictable plot whose aftermath leaves the town's men and women perfectly exposed to each other. Missakaela is avenged when the men are forced to admit their tendency to withhold approval except toward attractive women whom they objectify and possess.