After her party, Christine and her father are talking in her room. There is a close-up of the drawing of her father. In later shots, it is a different picture. The face in the picture is at a different angle.
At around the 53-minute mark, a shot shows a badly cracked floor tile. When an extra walks across the adjoining tile, it lifts up on one end and makes a SPLUNK sound when it falls back into place.