Unfortunately, it is impossible to cryptographically sign a physical object (like what, enumerating all of it's atoms and their positions?). NFT is only valuabl

Unfortunately, it is impossible to cryptographically sign a physical object (like what, enumerating all of it's atoms and their positions?). NFT is only valuable if the creator promises she will never sign any more identical objects in the future. And she is incentivized to do so by way of receiving royalties on all future resales.