After the ladies leave the party Niles orders two bourbons for himself and his brother. This is the first time either has drunk this particular spirit during the series.
Comment: Although this is indeed an unusual choice of beverage for the Crane brothers, I think the writers felt that "two bourbons" was the perfect drink for a couple of "noble bastards".
Roz: Listen, I have a favor to ask. This friend of mine is running this charity dinner dance Friday night...
Frasier: Oh, Roz, say no more. What do they need? An autographed picture for their silent auction?
Roz: That would be a silent auction!
Roz: Frasier's interested in Poppy?
Niles: I shouldn't be surprised the subtle signs of attraction are lost on you, a woman for whom the gunning of a Harley engine is like a come-hither look.
In Season 3's "Moon Dance", Niles and Daphne end their famous tango with Daphne on one knee before Niles. This episode mirrors that one in that Frasier and Poppy end their tango in exactly the same way, except that it is Frasier who is on one knee before Poppy.