This is the first time they actually show Freddie Crane, played by Luke Tarsitano, he will later be replaced by Trevor Einhorn, who will play Freddie for the remainder of the series.
The show opens and stays in the back corner of Nervosa. This usually indicates a large set will be used later in the episode that will crowd the regular apartment and radio station sets in the studio. In this case the toy store set.
The Act Two title card reads, "A Mall and the Night Visitors." This is a reference to "Amahl and the Night Visitors," a one-act opera by Gian Carlo Menotti. It was first performed on December 24, 1951 at the NBC Opera Theater in New York City and was the first opera specifically composed for television in the United States. The opera was inspired by Dutch artist Hieronymus Bosch's painting "The Adoration of the Magi" (c. 1475).
The celebrity caller in this episode is Ray Liotta. Liotta plays Bob, who calls from the airport during Christmas, unsure whether he wants to fly home, or hop on an open flight to Hawaii. After Frasier (Kelsey Grammer) counsels him, Bob says he has reached a decision, to which Frasier darkly replies "Mele Kalikimaka, Bob" (meaning "Merry Christmas, Bob," in Hawaiian).