David, I really like the idea behind the shot, I love the lighting and the tone and the nice 'Old Master' painterly feel to most of the image. I also don't find the subject matter confusing or ambiguous, as the image for me is simply about shape, texture, lighting, colour and mood, which you have definitely captured. However I have to agree with Jule, that your sensor needs a good clean and I will also agree and say that I am not at all keen on the corner thumb print style of vignette. Also when I view the image at 100%, the artefacting around the upper branches of the tree and the posterization and weird blocky coloured banding in the sky and fog are very noticeable, yet none of these artefacts appear in the foreground grassy area, which is both soft and pleasantly grainy.
So I as I say, I really like the idea of the shot etc, but there are just too many problems with this version of it to be a winner for me I am afraid.
If this is just the effects of using a very high compression ratio on a large dimensioned but low res image, then try resizing down to about 800 or 900 pixels on the longest side first, then save it out to a medium res JPG at a compression ratio of 10. You will end with something like a 150k to 250k file, that is small and easy to upload, yet still big enough for the forum members to view at a reasonable size, but not compressed to the point where it noticeably affects the image quality.