You don’t honestly believe that Joseph of Arimathaea, Nicodemas, and whoever else may have helped, left the cruel crown of thorns on when they wrapped the body, even though he was dead?
Wouldn’t you have been so repulsed by what the soldiers had done to your Lord that those thorns would have been tossed aside pronto when retreiving the body?
I doubt they were of the carnal mindset at that moment, saying, “Hey, we better keep the thorns on so he looks like he did while he was on the cross”.
Don’t forget the soldiers pressed the crown on, Christ carried His cross and fell several times, and His blood dried on His body in places. The cross may have pressed it in further when He fell three times.
My point is: it may not have been easy to remove it from His head by the time they got the body down. They were in a rush to inter Him before sundown. They may have just wrapped him quickly, intending to come back and remove the crown of thorns when they buried Him properly.
Or, Christ could have created the image on the Shroud that He wanted to leave with us: the image of the suffering He endured for us.