If the spread was that large, all the rest of the devices on both sides would look like that. As mentioned already, it is just coin damage. Note on the device next to that area, it is flattened. So the rule about incuse marks on a coin is the same with this one. 99% of the time, it is damage. Probably happened when a roll of coins were opened, several coins from the roll fell on that area. Note they are parallel?