Nice photo Mike. It does look like a ball signal to the right of the plow. If so, the questions are: When was it installed, what did it control (turnout, etc.) who changed it (probably the station agent) and when was it removed? The signal appears to be neutral as neither side is up so why was it in that position? Was this some kind of control for traffic over the bridge if so, what aspect is that?
As often happens, a photo raises more questions than it answers. Beautiful shot though with good detail of the platform and canopy.