RORY: What are you looking at?
LORELAI: I’m just trying to see if there’s a hunchback up in that bell tower.
Lorelai is alluding to The Hunchback of Notre-Dame, a Gothic novel by French author Victor Hugo which was first published in 1831. Set in the Middle Ages, the protagonist of the novel is Quasimodo, a hunchback who is the bell-ringer in the cathedral of Notre-Dame in Paris. It has several times been adapted to film. The most recent for Lorelai and Rory in 2000 would be the 1996 animated Disney version.
It is ironic that it is Quasimodo’s job to mark the time of day by ringing out the bells in the cathedral to mark the time of day, when Lorelai’s clock did not go off.