Full Idea
If we could duplicate 'Mona Lisa', we're likely to be concerned to track the original and keep it separate from its clones, even if we judge that the clone isn't inferior to the original when the goal is art appreciation.
Gist of Idea
If we could perfectly clone the Mona Lisa, the original would still be special
Source
Stephen Davies (The Philosophy of Art (2nd ed) [2016], 4.3)
Book Reference
Davies,Stephen: 'The Philosophy of Art (2nd ed)' [Wiley Blackwell 2016], p.85
A Reaction
But why? Is it just a sentimental attachment to what Leonardo worked on? Does the original manuscript of a work of literature have the same importance? We treasure such things, but not for aesthetic reasons.