JESS: Oh this? Nothing. [does an illusion with a coin] Just another little disappearing act.
We now learn that Jess knows at least one basic magic trick, showing that he must be dexterous and quick with his hands. (Something that would be very handy playing poker, as well).
It’s a reminder that he makes other things disappear with his quick hands – books, beer, money, gnomes … And no doubt a major foreshadowing of what is to come.
Clever Jess has already learned how to hook a girl’s attention: make himself unavailable by disappearing (as he did at the dinner). He is careful not to hang around and chat like some regular person after giving Rory her book back, either, but mysteriously pads off into the twilight.