More...just was reported that a locomotive was pushing this train from the rear...that’s very unusual...
It doesn't make sense to take the time to move a locomotive from one end of a commuter train to another every time the train changes direction, especially if the train is making a return trip shortly after arriving at a terminal station. NJ TRANSIT trains always operate this way, and in most cases they operate diesel service with the locomotive at the "western" end of the train (the direction is relative to New York City or Hoboken). This means the engine pulls the train on their westbound trips and pushes it on the eastbound trips.
I'm not 100% sure about this, but I believe this configuration is based on the layout of the NJ TRANSIT rail yard in either Hoboken or South Kearny, where the locomotive maintenance facility is located at the west end of the yard and therefore it's easier to have a locomotive at that end of a train when the train is put together in the yard.