In future episodes, evil cannot even touch the Book of Shadows (barring special circumstances), without it flying away. The evil shapeshifter manages to get it all the way to the threshold before it fights back. And, later, the book is handed over to the fake Victor without any reaction at all from the book.
Young Prue on the TV has dark eyes whereas the adult prue has blue eyes. Also in a future ep a young prue has striking blue eyes.
When the mailman forms a key with his finger, he forms a Schlage brand key, but the deadbolt from the inside of the door is a Kwikset brand deadbolt.
When the mailman morphs into Trudeau, you can see a crew member wearing a green shirt and sitting in a director's chair in a mirror.
When Prue walks in and sees the "morphed" Andy looking around the house, he starts walking towards Prue and you can see in the back right side of the screen someone sitting in the kitchen, even though the house should be empty.
@16 minutes in when Prue gets home to find a warlock posing as Andy you can see someone sitting in one of the other rooms to the right in jeans and a green shirt.
After the girls father leaves , they're sitting around watching a Christmas video and you can clearly see Phoebe as a toddler , but in the show where the girls go to the past , Patty , even though she is unaware of it , is pregnant with Phoebe and by then , their father had long since left .
When Fritz enters the house as the postman for the second time, Marshall has morphed into Phoebe and is sitting in a chair towards the center of the room. When he stands up and morphs back into his male form, he is suddenly standing by the window.