Since the Shroud of Turin has those exact poker holes burnt in it in the same L pattern, and the herring bone weave pattern, unlike any other, It most likely is the Shroud of Turin being shown.
There is also a medallion struck in the 12 Century showing the double sided Shroud. Then there is the description of the Shroud from August 14, 944 AD in the Sermon of Gregorius Refendarius in which he relates the double image of Jesus on the Cloth. . . on the arrival of the Image of Edessa in Constantinople at the Hagia Sophia. There are many representations of Jesus in which there are points of comparison that match the Shroud.
Then there is the 11th Century letter of Sir Robert di Clari describing how, on every Sunday, the miraculous image of Christ on his burial cloth was raised at the Hagia Sophia for the worshippers to see. The Burial Shroud of Jesus was listed in the inventory of relics in Constantinople before the Knights of the 4th Crusade sacked the city and stole everything not nailed down and even some of those things.
To the naysayers no matter how much proof or evidence they are shown they will still not believe it, kind of like the Jewish Pharisees of old.
Thank you for those facts— and the ping! The Shroud is here for those who believe in outward signs. Christ knew human nature needed tangibles to hold onto and instituted outward signs to give grace— sacraments! Why is it so hard for people to comprehend? He performed physical miracles and used physical materials to help with conversions. For me, the shroud is just another tool He left to help us understand.