Actually reproducing exact copies are not possible, because of how a hash works. An artist takes the original file and creates a sha-hash fingerprint, this is unique to the file. Now I could change one pixel of that artwork and hash it, and the hash would be different, then list that. However, if faced with two competing artworks one could easily determine the forged work because of the hash and the timestamp on the blockchain. I could easily say look, my art hashes to the first known version published to the blockchain, therefore any other copies may share the visual elements but are not the original.
This is no different to real artwork. There are many paintings of the Mona Lisa that look visually similar, but there is only one actual copy that holds value. Could a seller convince a buyer on a forgery, yes, but the blockchain actually makes this harder because of the immutable timestamps. I can know the original is the original because the original copies hash will always point to the first known appearance, and will have been signed by the artist directly. As long as the artist makes his signature well known, it is trivial to know which tokens are authentically signed.