Be Careful What You Witch For - S2-E22
Visible crew/equipment: While Leo is up in the attic with Piper, flying Phoebe, and teenage Prue, Leo explains what happened to Prue, and when Phoebe asks how it's even possible, we can see the stunt harness at the back of Phoebe's jeans as she rises in the air. (00:18:45)
Chosen answer: Her agent/manager negotiated a special billing as part of her contract. It distinguishes her from the rest of the cast, probably when she became a producer on the show.
JC Fernandez