From a modern perspective the veneration of icons, relics, etc., may seem a bit silly, but when placed in the context of widespread illiteracy, the visual vocabulary of Christian iconography can be recognized for the prominent role it played in illustrating, transmitting and communicating Christian beliefs.
Because of the reliance on iconography as a visual vocabulary to communicate specific thoughts, stories and traditions, an artist's value was largely gauged in terms of consistency and conformity, not creativity or innovation.
What's unique aout the shroud springing forth in this environment is precisely its lack of precedence.
Indeed.
A Medieval Forgery would have reflected the Conventional Iconic Images of Jesus.
The nails, for example, would have been in the center of the palms, not the wrists. The face would have been more European than Semitic, and there would have been other details that would have been in line with contemporary interpretation of the Gospels.
The Shroud, compared to other Liturgical Art of the Medieval period, is just plain DIFFERENT. A forger would have made sure to have his image conform to the accepted norms in order for his “counterfeit” to pass muster.
If I were to make my own Twenties, for example, I would NOT put Obama on them. :-)