Image by slambo_42
On the prototype, when one train is stopped in a siding and another passes it, the stopped train’s crew will normally stand outside their train and watch while the other train passes for a quick visual inspection of the passing train. This practice, called a "rolling inspection," helps the railroad spot problems on trains when they’re between stations.
This little guy was waiting patiently on the chair for several minutes until the train came by. Then he and his mother took a good close look for their own rolling inspection as the train passed.