There was a thread in my Canon Photography forum (POTN) discussing the use of the Auto/Green box mode compared to "preferred" settings. So, I grabbed my trusty old EOS 30D. In Manual Exposure mode I exposed this shot for the sky and set my aperture to f/2.8 to get a soft background. I wanted to get "good sky", knowing that my Raw converter would massage the exposure variations. So, the first two images are the Before and After of the one shot.

Then, I switched to Auto. The camera popped up the flash and used settings that not only overexposed the sky but also a "medium" aperture the made the background trees more "focused".