If one listens closely to the phrasing, ambience and vocal performance of Ann Morgan Guilbert's 'Sentimental Love Song (My Love Got A Smash in the Face)' during the auditions, it is evident that her's was one of the few examples of a live singing performance on the series, without being pre-recorded or dubbed.
In the special features section of this episode on the DVD series collection, there is a rare color photograph of the set and characters during Mel's (Richard Deacon) ventriloquist audition. Mel and his dummy are wearing bright red jackets, Rob is wearing a dark blue jacket and light blue pants, Jerry is wearing green, Anita's dress is blue and Sally's dress is gold.
Sylvia Lewis (who played "Anita") was the ex-wife of John Rich, who was a frequent director of The Dick Van Dyke Show. He did not direct this one though.
The choreography and costumes for "A Doodlin' Song" was inspired by "Steam Heat," a number from the 1954 musical The Pajama Game, choreographed by Bob Fosse.
During the penguin dance, Anita's left hand is obviously seeking Rob's hand. He holds it for about two seconds during the dance routine.