Louisiana
Oswald's childhood and life are set in Louisiana, so his participation with that environment comes through as imagery. The complicated life he lives leads him to join the USMC where he serves and leaves feeling disenfranchised and frustrated by having risked his life for a government that makes decisions he disagrees with. His life in Louisiana is mostly normal, shockingly.
Dallas
The imagery of the shooting is really well known because it was video-taped. The setting of the assassination and the setting of other scenes in the novel bring the reader into the world of Dallas, the banking and investment heart of Texas. The idea of big business and money is inextricable from the imagery of Dallas, because the city is enormous. The urban domain is the broader setting for the minor setting of the drive on which Kennedy was assassinated. The footage is famous, but also very gruesome, and so is the depiction of it in the book.
Politics through imagery
Kennedy is an image of American authority, making the assassination a horrifying and disturbing event in the history of the nation. But that is not the only depiction of politics. Oswald's service in the Marine Corps, his frequent participation in the Communist party, and the various accounts of the CIA and the executive branch are all depictions of government and power.
Death and horror
The imagery of death and horror is contrasted with the imagery of daily life, but DeLillo is careful to leave the two kinds of imagery in close union, because he is suggesting in the novel that regular life is as deathly and horrific. In the same way that conspiracy theorists see layers of meaning in the death of Kennedy, DeLillo suggests through imagery that real life is as layered and complex as the murder.
