When Mel leaves Niles at the cafe, he says, "I'll see you at Schwanda die Dudelsackpfeifer." The correct name of the opera is "Schwanda der Dudelsackpfeifer."
Frasier's new station manager, Todd, is so enamored by Frasier's sense of style that he recreates his own apartment to look exactly like Frasier's. It's hard to believe that Todd would have been able to acquire the same paintings Frasier owns--not to mention the same African art and statues--in such a short time (and without leaving the country!).
At approximately 7 minutes in, the camera angle is far too high and clearly shows the set walls above the fireplace.