When Frasier and Leland are drinking sherry, Frasier describes it as an "Andalusian Amontillado". All sherry is from Andalusia; their drink is a pale straw color (probably Fino), whereas Amontillado is an oxidized variety making it a rich brown.
Frasier refers to Brassaï as a "Romanian master". Whilst it's true that Brassaï was born in what is now called Romania he was, in fact, a French and Hungarian national, having studied in Hungary and served in the Austro-Hungarian army during the First World War.
At the beginning of Act 1 Scene 2, Roz, Eddie and Ariel enter Frasier's apartment and the two dogs run into the kitchen together. Although Eddie appears twice later in the scene, Ariel is nowhere to be found.