The phrase "the island of Manhattan" is a literal description rather than figurative language. However, if you’re looking for a figurative language type that relates to how Manhattan is often depicted in literature, it might be best associated with metaphor if it's used to symbolize something beyond just the physical space. In general contexts, "island" could imply isolation or uniqueness, which can take on metaphorical qualities.
However, based on your provided options, if the intention is to choose the closest answer, Metaphor would be most appropriate.