What to me is a little distracting in the top one is, the size or weight of the distant dune is too equal to the space at the bottom. It would fit, with a little tilting, pretty neatly into that space. I like the division of space in the cropped version better. And I agree, my first thought also was that space in the uncropped version somehow does look like it would suit for copy of some sort. I keep thinking the distant dune looks like a pencil, not it that it matters. In this instance, in the top one, my eye keeps going from the expanse of space at the bottom, to the upper too similar in space portion/ distant dune.. then back, then to the dune again, what to me is in a conflicting but way. Maybe I am looking at it very abstractly. Both are nice, but as I said, to my eye a few distractions in the first one. There is only some slight cropping but it does change the look, and I think, maybe subtly the mood or feel of the piece.