At the end of the recording session for "Forever Darling", Ricky and each of the Pied Pipers turn away from the microphones until they hear the 'all clear' from the session manager. Before the age of digital recording this was done to avoid any unwanted sound from the singers' breathing or other movement around the microphones.
When Lucy and Ethel are trying to come up with a name for their impromptu raffle (to raise money for their own trip to Europe), Ethel suggests, "I don't suppose we could call it 'Two Bundles for Britain'?" This was a reference to the World War II program in which food, clothing and other supplies were sent to support British soldiers in the first years of the war (1939-1941). After the United States entered the conflict in 1941, the group became known as Bundles for America.
Ricky's recording session with the Pied Pipers (singing "Forever Darling") takes place in front of a control booth labeled "MGM Records". As Ricky leaves the room, there is a toy stuffed lion sitting on a chair next to the door. He pats the animal on the head, and says, "Goodbye, Leo" - the semi-official nickname of the MGM lion seen at the beginning of most Metro-Goldwyn-Mayer movies and shorts.
The name of the raffle winner is a nod to Hazel Pierce, Lucy's stand-in.