I assume it means that it was tooled to make it look like a better grade. A couple examples from Heritage are more obvious. I didn't find a specific definition on PCGS. OP coin seems to have lines through the hair and behind the ear that were added, but it's hard to tell.
https://coins.ha.com/itm/flying-eag...1618-21464.s
https://coins.ha.com/itm/seated-dol...1446-25382.s
https://coins.ha.com/itm/flying-eag...1618-21464.s
https://coins.ha.com/itm/seated-dol...1446-25382.s