A literary technique in which two or more ideas, places, characters and their actions are placed side by side in a narrative or a poem for the purpose of developing comparisons and contrasts. A useful device for writers to portray their characters in great detail to create suspense and achieve a rhetorical effect.
Photographically, when two things are placed together for effect; or when two things being seen or placed close together for contrasting effect.
It is a human quality to comprehend one thing more easily by comparing it to another. So when you look at the bouquets of flowers compared to a handsome robot, ponder the deeper meaning.