The original unaired pilot was filmed entirely on location at 1329 Carroll Avenue (the house used for all exterior shots and filming for Charmed). Once the role of Phoebe was recast to Alyssa Milano, shooting for the interior shots of the house took place on a sound stage. One shot from the original unaired pilot does remain in the aired pilot: when the sisters receive their powers and powerful blue lights radiate from the chandelier in the living room. This shot was filmed in the actual house on Carroll Avenue.
In the original pilot that was unaired, Phoebe was played by actress Lori Rom. After Lori left the project for personal reasons Alyssa Milano was recast as Phoebe, and all of the shots that starred Phoebe were reshot. Many of the shots from the pilot that did go to air were from the unaired pilot - these shots featured only Shannen Doherty and Holly Marie Combs. Shots with Alyssa or shots with all three actresses were reshot.
Inspector Andy Trudeau ask if the cat that Phoebe is holding was there and that it "seems familiar." For three seasons, Kit appeared on the show irregularly and was the witches "familiar". In folklore, familiar spirits (sometimes referred to simply as "familiars" or "animal guides") were believed to be supernatural entities that would assist witches in their practice of magic.