Factual error: Chucky murders his first (human) victim as he was taking down the Christmas lights, making him fall in the watermelon patch in front of his house. Shane must have an uncanny green thumb, to be able to have fully grown watermelons in winter.
Factual error: After Detective Mike looked at Shane's body, the camera shifted to an aerial view of the city, which showed Fall foliage but it was after Christmas, when the trees in Chicago would have already shed their leaves. (00:40:50)
Answer: I wouldn't read into it much more than just a joke: Chucky heard that joke earlier when the kids in the street were trying to make him do things for their cell phone cameras. So he just re-used it later as he often does in the movie.
Sammo ★
It was a joke that some kid said when he had the Chucky doll.