At one point Paige says to Kyle "Don't worry. Magical things happen to us all the time, but this is the first time in black and white." In Chick Flick (2000), and Piper and Phoebe were both in black and white when they got sucked into "Kill It Before It Dies" by the Demon of Illusion. However, Paige hadn't met them at that point.
When Paige and Brody arrive inside the book, the car license plate indicate they are in New York. In the distinct background, there is a palm tree.
After doing the gun powder test on Miss Donovan, Brody says definitively that she couldn't have killed the gnome. Any trained investigator would know a negative result is not conclusive because she could have washed her hands.