Okay, so as much as I hate pointless speculation... I'll bite. These things just look way too temporary. If the concrete things have been there a long time (they look like it), and if light poles were there before (which would make a lot of sense), maybe they are simply adding new light poles? The box on top is made of plywood, for goodness sake. Seems like it would be a good temporary cover for whatever light pole wiring and base that would be exposed to the world without a nice box covering it up. Furthermore, the first photo shows a similar piece of plywood covering the side of the concrete base, which seems to me like it could simply be an access panel for the wiring.
I think the camera idea has been debunked (shots wouldn't be that thrilling, movement isn't regular enough to be able to produce reliable photos, wrong side of the fence) and I'm just not buying speakers, considering Disney can easily hide speakers better than this and there are no holes for the sound to come through...