Negative space

I took this photo during my recent Bellingham photo trip and thought it was a good example of the use of negative space.  The two different areas of black are still recognizable even though there presence on the same image plain results in ambiguity of scale.  I wonder what anyone observing me thought as I moved around making slight adjustments until I felt I had the right angle.  Fortunately I don’t worry about such things while I’m shooting.

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