When Colin is standing at Sydney's doorway, one can clearly see a stone wall near the front doorway, and that the door's framework is brown with glass windows. When the scene switches, the front doorway area is blue siding and the door is a solid door which opens the opposite way.
When they slide down the toboggan slope themselves, the toboggan is wood colored at the top of the ramp, but red when the come to a stop.
When Colin says, "I think she was a little confused about my name, though," about the person who recognized him, his mouth movements do not exactly match the words he is speaking.