I can't help but fantasise about Half Life 2 being more like the environment in that second shot. Imagine walking out of the train station in to the plaza for the first time, with a pale winter sun shining through the slow, dirty sleet, the ground covered in a thin layer of filthy snow and ice. Rather than just a dystopia, it could be a bitterly cold dystopia, further displaying just how much the Combine have destroyed earth.
I do realise that the image is just grainy, and it isn't actually snow, but still!