One of the "mannequins" in the Department Store represents the First Lady at the time, Jacqueline Bouvier Kennedy.
While Barney plays the piano at the Ambassador's Ball, his costume changes from black tie and tails to his everyday brown tunic and back again in the next scene.
ABC Originally Broadcast This Episode In Black And White
The mannequins in the department store are based on Maria Antonelli, Jackie Bouvier Kennedy, and Christian Dior.