The photograph Amy finds in the drawer is seen in closeup to be a portrait of Irena. In long shots, however, it looks more like a wedding picture with one person in white and another in black standing side-by-side.
When Oliver first drops the photographs onto the fire, they land to the right side of the flame on a log. However, in a closeup on the fireplace, they are in the center of the log where the flame is located.
In the Reeds' house, there is a small side table with two figurines and a vase to the left of the front door, near the closet where the coats are kept. This table varies from having a backboard on it (after the carolers come into the house) to lacking one (when Oliver takes Amy outside to look for Irena) but having the backboard when Oliver brings Amy back inside, and again not having it later when Amy flees the house).
The vehicle that passes Amy on the bridge leaves no tracks in the snow next to her.
When Miss Callahan runs to the phone to call the police to report that Amy is missing, she dials O for the operator and begins speaking as if the call was answered on the other end of the line; however, the rotatory dial had not stopped before she begins her conversation.
(at around 57 mins) A crew member can be seen in the window on the right, walking out of view as Amy calls for Irena.