The guest experience does not end after the guest has consumed their last morsel. Everything that occurs from the presentation of the check to the time the guest physically leaves the confines of your space (i.e. drives or walks away) or munches on the last remnants of their doggie bag is part of the experience.
Too often, a perfect meal is tarnished because the restaurant failed to follow through and close out the guest experience in a congruent fashion. The last memory tends to be the one that has traction.