During the episode’s unexpected climax, Agnes reveals to Wanda that she is actually a witch named Agatha Harkness.
Each shot from “Agatha All Along” can easily be identified as belonging to a particular previous episode based on the costumes and background decor.
Yet, that is exactly what happened in episode seven of WandaVision, which ended with the song “Agatha All Along”, a sitcom jingle that revealed the chilling truth about Wanda’s quirky neighbor Agnes.
According to Hall, the scene needed for the montage was frequently shot in a different manner from the rest of the episode.