According to Urban Dictionary, an Easter Egg is "A secret, hidden inside a video game, DVD movie" etc.
Google evidently placed a camera on the tender of a Strasburg RR locomotive in October 2015. If you click anywhere on the track between Leaman Place and the Strasburg station you can "board" the tender and see a 360° view.
Here is a link to the view at the Leaman Place end of the run.
You can click on the little X to move forward, or turn 180° and click on the X to move in reverse.