Kiernan Shipka's actual stand-in plays Sabrina's stand-in the alternate reality. She also plays the other Sabrina from behind in over-the-shoulder shots in scenes with both Sabrinas.
Caroline Rhea and Beth Broderick play Aunt Hilda and Aunt Zelda in the alternate reality. They also played these roles in the original series, Sabrina the Teenage Witch (1996 - 2003).
The actual sets are used as the sets of the TV show in the alternate reality.
The cat of the alternate reality is called Salem Saberhagen, which is the same used for the cat in the original series Sabrina the Teenage Witch (1996)
Prudence and Agatha wear the same cheerleading uniforms they wore in Season 1, Chapter Five: Dreams in a Witch House.