Jeff is eating a sub sandwich with a type of rye bread, however, when he passes it to Casey, the bread changes to white.
Subway is a national chain, and all their stores operate the same. When you enter, you are at the bread end of the assembly line. They build your sandwich/wrap to your specifications. Once it's made and wrapped in wax paper, the person at the cash register asks if you would like drinks, chips or any extras to go with your sandwich/wrap. Then, they take your money. They do deliver it to your table in some stores, but they do not ask you to pay at the tables.