What are talking about, the originals are half resolution compared to yours ? Even your file you provide for us "original" is in 50% size compared to yours, can't you see that ?
I can resize for myself but maybe someone doesn't cuz ot have transparency.
And it look like it miss bump mapping ...or something too. It doesn't have that "bluish" colour like original do. Maybe that's why it's "affected much more by light and shadows".