(They both take sips of coffee at the diner)
RORY: Huh. Does it taste different to you?
LORELAI: Yeah. It does.
Lorelai has convinced Luke to commit to Rachel, and now she is staying in Stars Hollow. Unfortunately, Lorelai and Rory notice that the coffee tastes different now that Rachel is making it. Uh oh – they need that special coffee as made by Luke!
Viewers can tell that Rachel probably won’t be staying around very long, because no way can the Gilmore girls go without their favourite coffee. It also suggests that, as Luke and Rachel are using the same coffee beans in the same machine, there is nothing particularly “special” about Luke’s coffee, and that what Lorelai and Rory really love is Luke himself.