Did you get it right?
The two basement model-railroad panels contain five visible changes.

The Answer
The correct answer is: five changes involving the station clock, tunnel stones, locomotive stripe, control lever, and trestle brace.
Here is why
- The station clock hands point to a different time.
- The stone arch around the tunnel has a different number of blocks.
- The locomotive has a different yellow side stripe.
- One control lever points in a different direction.
- A diagonal cross-brace beneath the trestle changes angle.
Why people miss it
The warm room, family members, tracks, and miniature scenery are closely matched, so the eye is drawn away from the small mechanical changes.
What answer did you get before checking?