So you'd place value in a cryptographic signature from the author that ties the piece of paper in my analogy above to the photo of their real life signature? Ho

So you'd place value in a cryptographic signature from the author that ties the piece of paper in my analogy above to the photo of their real life signature? How much would you value that at, given that anyone else can acquire and enjoy the exact same photo of the signature that you enjoy, just without the piece of paper saying "this photo that everyone can see and enjoy is owned by andypants"? If the value you'd place on that piece of paper is above zero, why? (Genuinely curious).