Photographs of haystacks prove nothing: by definition they are made up of any number of uneven and conflicting lines, spikes and angles of which very few can ever lie in exactly the same plane, so how can any camera focus properly, especially if in one of those silly autofocus modes? I believe that the photographs shown prove this, at least to my satisfaction.
As for using images of birds! I ask you, who has the slightest idea how sharp or otherwise a bird might really be? Think of it, seriously: where are its edges?
It's not by accident that the best photographs in photography are of unadorned, unplastered brick walls.