As you can notice if you do the comparison (see on my blog), the non-adjusted version is clearly over-exposed. In fact, — as I explain it on quite many of my pictures — it's a photography technic where you help your camera to grab as much details as possible, specially on shadows, because camera sensor are way more efficient on highlight. It's also called to “expose on the right” (meaning right of histogram). For sure, this technic implies two thing: you must master your exposure to be sure not burning highlight and permanently loose details by keeping your settings to the limit. Also, the shot will require more time on adjustments to post-prod your picture back to your original feeling when taking the shot.