I think what is "missing" is a level horizon. This photo is made up of mostly rectilinear lines, in a rather formal,predictable pattern. The fence and seawall are rectilinear. Everything is pretty much a straight line, or nearly so. Very formal, repeating, rectinlinear shapes for the most part...and then here comes Big Twinky with the horizon all tilted...
To me, the horizon's tilt just kills the photo of a desolate, closed marina and a bunch of empty boat slips. I dunno...the small amount of sky in the URC has a lot of weight, and the ULC has no weight, and the dissonance introduced by the background just *kills* the formal nature and the repeating forms in the foreground and middle ground....one of the single biggest design elements in this photo is the design element of repetition. But the loss of the repetition in the near background just kills that...it introduces an excessive amount of another design element, dissonance, and that dissonance overrides the repetition quite easily.
It's like a loud cougher at a string quartet performance...it takes only a little coughing to mess up the sweetness.