Oh my god a Royal Sub is fantastic, its the best sub. It's italian sausage and capicola. Usually melted with provolone, or maybe mozz. It looks like that might be homemade italian sausage, which would be phenomenal. The royal sub inspires my favorite sandwich to make at home, which is an italian sausage link grilled, prov melted on it, and nestled in a hard roll in a bed of capicola. I usually top that with peppers and onions, whereas a royal sub would be lettuce tomato and onions.
In my experience, you really can't buy Italian sausage patties around Atlanta. I've tried making them a couple times with poor results.
But the best part...the rolls they are talking about are undoubtedly from Constanzos in Buffalo. And they indeed are unparalleled. If you grow up eating subs on Costanzos rolls in Buffalo, you'll miss them your whole life. They also make the best burger and weck rolls.
There was a pizza place here north of Atlanta about 15 minutes from me that had Buffalo style stuff, and he too used to get the sub rolls shipped from Costanzos. But tragically they closed during the pandemic.