Trivia Continuity Error

After Doris has had a chat with Coco in the School corridor, she passes Dwight and gives him Coco's sandwich. A Group of dancers can be seen by the cafeteria doorway practicing steps. One of them is Marguerite Pomerhn (Derricks).

As Doris enters the cafeteria Marguerite can be seen clearly.

On entering the cafeteria Immediately afterwards Doris looks around to find Bruno, who is sitting at a table talking to Marguerite who is now wearing different clothes.