When they're confronting their mother over the events of the previous episode, it's subtly shown that Glen's eye twitches when they're anxious or stressed, just like in Seed of Chucky (2004).
As described in the behind the scenes video, Jennifer ending up in Tiffany's doll body was implied by the spell being cast calling for a switch, not just a transfer.
Tiffany calls Glen "sweet face" as she did in "Seed of Chucky" (2004).
The letters of the opening title are made up of stuffed animals of varying styles and colors.
Tiffany still refers to her murderous tendencies as an addiction.