It most certainly is the shroud of Christ, but God will never allow His existence to be captured proof positive in a jar like a lightning bug.
The true value of the shroud is that it causes such consternation amongst those that refuse to see. It is such willful ignorance that separates the goats from the lambs.
Christians don't require the shroud to be genuine to validate their faith; atheists on the other hand are presented w/ powerful evidence that their non/beliefs are absurd.
I admit to a guilty pleasure in watching them thrash about concocting theories of medeaval geniuses inventing photography merely to play a hoax and never replicating the process.
One can only approach God on one's knees, and never through arrogance.
Nothing could be further from the truth. True faith has nothing to do with this piece of old cloth.