In his famous 1936 essay, The Work of Art in the Age of Mechanical Reproduction, Walter Benjamin describes how art was historically used for ritual purposes. Because the ritual value of art was tied up with its uniqueness, it was unthinkable to reproduce a work of art.
In some respects, this phenomenon continues to exist today, particularly in religious contexts. Every year, up to a million pilgrims walk to the town of Fátima in Portugal to witness a parade in which the statue of Our Lady of Fátima is displayed.
The development of technologies of mechanical reproduction means that it would technically be possible to produce a close copy of this statue, and of course, with photography, millions of images of the Lady circulate around the world freely.