Some goofy answers above. But oh well. Other details:

Switch in foreground appears to have a sprung frog.

In the distance is a ground-mount type search light, or "Pot Signal" mounted to a pad on the ground. Per the SLO RR museum website, "signals like this were often used by the Southern Pacific on sidings to govern movement over the switch leading back onto the main track." That leads me to wonder, what track did the signals on the tall pole govern? Main track?

Whatever the crossover was for (helper moves?) I imagine there were special instructions how to use a hand throw cutover between siding switches, esp. if this was CTC territory, and maybe there was dispatcher phone here outside the photo frame.