I've got a Postwar 3454 Pennsy Merchandise Car, and that's the way this car works too. The door slides open, and that door slide part of the mechanism is connected to a cam. You get four (or five?) kicks from the box ejector part, and then the door closes. Of course you just press the button again and the door opens back up and kicks out the remaining Baby Ruth boxes, but you need to also hit the button a few more times once its then empty to get the cam to work back to where it should shut the door again. If Lionel does have some kind of new can motor mechanism inside this car, it sounds pretty cool that they went with copying this original way the car worked. I suppose doing it this way would give a kid an unload and a half, or pulling the car to a stop twice before it was empty, instead of having to reload each time.
Sam
Here is a video I made of an origional postwar 3454. 6 boxes are loaded and all six will eject before the door closes. Each time the button is pressed one box will eject.
Very nice video. Six crates and not one landed "This Side Up" correctly! I guess the choice is hand over 1/3 of the load to the carrier or risk the damage <G>!