If the picture was taken from the head end of the train facing rearward towards the hind end, the signal would be properly indicating
"clear" for that direction of movement, and "stop" for the opposite direction.
Appears to be a pretty much standard "lower quadrant" train order semaphore. These kind were operated by cables hooked to the blade side of the pivot, and the blades were normally held in the "stop" (horizontal)position by the round counterweights at the opposite ends of the blades. The operator hauled down on a handle or lever and hooked it on a hook inside the station to pull the semaphore blades downward and "clear the board".
This was a "fail-safe" arrangement
so if the handle or lever slipped off the hook or the cable broke, the signal would automatically assume the "stop" position, causing only a delay to a train to find out it was a false indication, rather than falsely displaying a "clear" indication upon a malfunction and allowing a train to pass when it should be stopped.
At dusk, the operator got to light a kerosene signal lamp, climb the pole with it and set it on top of the semaphore mast so it would indicate white or "clear" except when the blades were in a horizontal position where a red lense would be positioned in front of the lamp to make a "stop" indication appear.
Generally, if a train came along and encountered a "red board" the engineer would"call for signals" (four short whistle blasts).
If there were no orders for the train, the operator would simply haul the signal blade down into the "clear" position and the engineer would respond with two short whistle hoots and proceed.
If there were orders for the train, to signal a train forward against a stop signal (such as if there were "19" orders to hand up), the operator would "dip" the appropriate semaphore blade momentarily to the "clear" position and then return it to "stop", hook it, then go out on the platform with a yellow flag or a lamp and hand up the orders or a clearance.
