I have not followed the comments of people on this page… But here’s my personal opinion on the Vignon’s marking issue:
In William Meacham’s paper « The Authentication of the Turin Shroud », he cites Philip McNair, a Doctor in Philosophy who studied the history of Christianity, who said, very cleverly: “It seems to me otiose, if not ridiculous, to spend time arguing… about the identity of the man represented in the Turin Shroud. Whether genuine or fake, the representation is obviously Jesus Christ.”
And why could this man [have] said this with so much confidence? Because of the great similarity that exists between the Shroud man’s face and the most common depictions of Christ in ancient Byzantine art, starting with the Christ Pantocrator icons. Vignon could have been maybe wrong on some points (in fact, I’m pretty sure he was on a few), but if we look at the global portrait of the situation, he was certainly correct: Most of the ancient Byzantine representation of Christ (and of course, I include the Mandylion in that group) are showing great similarity with the face on the Shroud. So much in fact that it’s certainly not a coincidence due solely to hazard. It’s evident that there’s a connection there that is strong enough to be taken as a good piece of evidence for the presence of the Shroud as early as the apparition of the first known Christ Pantocrator icon, around the year 500 A.D.
Note: Image is a clipped region taken from an image in Wikimedia and flipped 90 degrees clockwise. It “is a faithful photographic reproduction of a two-dimensional, public domain work of art” and is thus in the public domain in the United States.