Something audiophiles go crazy over and music lovers don't notice as much.
Something that has caused folks to buy speakers and then get absolutely sick of their distortion and other problems.
Something audiophiles can argue about and debate whether it really exists at a concert.
Something that one of the biggest speaker companies accomplishes, as the expense of higher distortion due to how they use the drivers, to get certain sounds float in the air, and distract them from the inherent problems with the speaker.
Something that keeps audiophiles' heads locked in a single position whole listening to the equipment (as opposed to music).
Those are some of the things that imaging is.