Continuity mistake: As Catherine is about to leave Frasier's apartment near the end of the episode, you can see the white shirt she is wearing constantly changes between shots. At times it is hanging out very loosely and in other shots it is neatly tucked in and positioned to the right.
Continuity mistake: When Daphne is setting up the soft ornaments along the top of the fireplace for the Christmas photo, she is just putting the first one on the mantelpiece, then the shot changes and she is positioning the second ornament.
Continuity mistake: When Katherine confronts Frasier in the hall at KACL, her purse strap is over her forearm. But when the shot goes to Frasier, from behind her, the strap is over her shoulder.
Chosen answer: The turkey's stuffing.