you see, that's the difference between you and me. you think like a photographer (which is normal, you'd say) and i think like a... (a what, already?) i won't say a painter, i'm not, but those white spots don't bother me at all, in fact they respond quite well to the white of the shed. maybe i think in the terms of the image, simply. look at this yellow field! but mostly, look at this light! you're totally right about the shadows being almost the same, contributes to create the illusion of reality -still knowing it's not- this creates a "malaise" which works very well towards the subtle surreal quality of it.
the only thing that bothers me is the grey color of the clouds above (of course, as a photographer, you got them right. i'm talking as a painter
) lol
for me, it IS perfect as it is.