Damage. If it was a strike through of something laying only in the device, it should be strongest in the areas of shallowest relief. So it should be strongest at the back of the neck and weaker on the front of the neck, point of bust and hair curl below the ear. Exactly the opposite of what we are seeing.
On the other hand if something dented the struck coin the impression would be greatest in the high relief areas and weakest in the low relief. That is exactly what we do see. Heavy on the point of bust and front of neck and the hair curl, weaker on the back of the neck and nonexistant in the field.