Note the date and all other devices are also looking smaller than usual. This is form a heavy die polishing. If the devices were looking wider and flat, then it would be a struck through grease issue on the die. There is an appearance of ridge ring, so that is the die showing DDD (Die-Deterioration-Doubling), but it just getting started. The 9 is showing a contact mark on that digit. Spendable coin. (always nice to know why it is spendable.