The episode title refers to the notorious 1980s R & B vocal duo, Milli Vanilli, that was exposed as two dancer/models who were fraudulently lip-syncing to other musicians' singing on their singles.
The Ponytones could be a reference to the Deaftones.
Friendship Report: Fluttershy learned to face her fears and be the best she can be.
The scene where Fluttershy is revealed from behind the curtain is reminiscent of the finale of Singin' in the Rain (1952).