Good afterns on,
Whilst I still think along the lines of lighthouse/foghorn on the area to the right and out of sight of us. Another possible is coastguard lookout.
But let's think about orientation, where is the open sea, is it behind us or out to the left. I'm starting to think out to the left. This may actually be on mainland terra firma and not a lump of rock in the sea.
We could just be looking across a bay with the shore line coming around out of shot on the right.
Why or what is the shot of, who just takes a single picture. It may be one of several which we don't have but would give us a location immediately.
There is something out of shot at the bottom, jetty or boat. Whatever it is has a post and what looks like large lookout binoculars but they are too low down to be shore based looking out to sea.
John915