hhhmmm
Since this took me seconds to edit in phothoshop,
I'm going to have to say that there is really no lighitng downgrade, I believe it has something to do with the contrast of the images and abvious compression being lost when
some images get imported depedning on the image software or compression tool. I've seen this happen many times with Color 2001 coated images from Asia or Japan and when some get imported to USA SWOP default color profiles,and thus this tends to happen.
If I recall many people praised the jumbo tron offscreen picture someone took not to long ago and many pointed at the fact that those usually have higher contrast.
NOTE: I didn't modify anything, other than the contrast sliders.