little-lotthe:

Christines Costumes: IL Muto Costumes 

This is the same costume used in the roof scene, is used during the Applause right before the chandelier hits the floor, and this is where she wears the 18th century powdered wig. The applause is presumably after she played a successful performance to the Countess. Therefore some refer to the customary for the “Countess dress”…more details