"Mama" was a quart bottle, and "Papa" was a half gallon. (The image of the young boy featured on the "Junior" size bottle is Barney Berns' son, Gene.) A common promotion in the 1940s was the 1 cent sale - purchase the Papa half gallon at regular price and get the Mama quart for 1 cent.
"Mama" represented a quart bottle, while "Papa" stood for a half gallon. (The image on the "Junior" size bottle depicted Barney Berns' son, Gene.) A typical promotion in the 1940s involved offering the Papa half gallon at full price and receiving the Mama quart for free with a 1 cent discount.