A unique item displays the value of something rare, the aura of a piece of art and the radiance of the individual. Being part of a sequence doesn’t lessen those effects, because the sequence itself can also be understood as a unique item. This is especially true for a sequence playing with variables that are based on a system, when single objects gain their form only from the relation between them and from the relation to the basic idea.
A duplicate lacks the value of something rare, the aura and the radiance of being unique, because another version of it already exists, a similar, but earlier, thus a more original version. But what if a complete sequence were to be repeated? Would it not be included in the rhythm of variations, whose superior system is called reproduction or duplication?