I think that it is just the method and type of camera used. They used box cameras in "ugly" outdoor housings. Most airports use dome cameras recessed in the ceiling with smoke bubbles so you can't see them as much. Some also use multiple box cameras in a single bubble in the ceiling. You can often count a dozen or more cameras covering a security area (BWI, BOS, PVD). Usually, they have specific needs - such as viewing the front and rear of the x-ray, the metal detector, the queue, etc...
I think this picture is an example of poor planning and possibly just adding on and on without re-thinking the best solution. Another example is DEN. They have Axis box cameras mounted to the wall (by the train) and on pillars. The problem is that they re all exposed and some are in easy reach. You could move the camera or disconnect the lens or network cable. You also know exactally where it is pointed, and can see the blinking network lights, etc...
My guess is that the lowest bidder threw something together and a security expert or consultant was never consulted.
Picture of DEN. The ceiling is about 100 feet up, so the box cameras are mounted to short pillars. http://media3.s-nbcnews.com/i/streams/2013/November/131113/2D9676693-131113-tsa-security-hmed-1030a.jpg
Maybe they need another camera... :)