Shrek and his family watch Tutti insieme appassionatamente (1965), starring Queen Lillian. Julie Andrews starred in Tutti insieme appassionatamente (1965) and played Queen Lillian in the Shrek films.
This film establishes that Mongo the gingerbread giant died in Shrek 2 (2004), although he was seen singing at the end of that film.
When the Pied Piper puts together his flute, a white glove can be briefly seen on it. The white glove was Michael Jackson's trademark symbol.
When King Harold rises, he catches a fly in his mouth. This is an homage to the SoBe Life Water "Thrillicious" advertisements, which feature a group of lizards dancing to "Thriller" (one of them notably catches a fly in its mouth).
The short was also released on the Nintendo 3Ds.