I think those are IR motion detectors.
They way they are placed if I see that photo correctly is that anyone walking towards the building would set it off. (photo 18)
They are photolectric.... its just a fancy name for overpriced motion detector
There's more of a difference than that.
Photoelectric strictly speaking is a modulated (usually infrared) beam between a transmitter and receiver (or can be reflected, with both T & R in one housing). When something passes through the narrow beam breaking it, there's an alert signal. Alignment is fairly critical with this type, but they work well as long as there isn't too much ambient light interfering with the beam(best indoors). Not really a motion detector in the true sense.
These units look like passive infrared (PIR) motion detectors, which don't produce a beam but monitor for changes in IR radiation over a wider area, like when a warm body or vehicle enters/passes. I see 2 mounted to this stake, at right angles to each other.
This is a pan/tilt/zoom patrol camera which can be operated remotely and/or set to continuously scan a programmed path. Pretty sophisticated stuff. They cost $1500-2000 apiece. The hot setup is to hook these up to a controller triggered by PIR or beam sensors directing them to follow and record detected motion events.
I don't know what this smaller device is. Possibly a fixed camera to continuously cover a specific area while the larger PTZ dome is free to scan a 270 degr area on both sides of the corner, or maybe its an IR spot illuminator.
The box like things are weatherproof camera housings. Sometimes they're mounted on pan/tilt platforms, but these appear to be fixed.