Again, improved lighting makes the details of landscape in the distance, as well as the horse and cart, much easier to see. Again, the skies are a much deeper blue, trees in the far distance look a trifle less cartoony, and the lighting of the landscape in the background gives more feeling of depth than the original. The lighting looks much better as well: it feels much more like actual daytime. Here's a glance toward Solitude, and in addition to slightly lusher plants and considerably bluer skies, you can see some additional details on the buildings, particularly the windmill in the top left corner. The water looks less greasy and oily as well. The sky is more blue and the yellow of the leaves is brighter.
This was taken near Riften, and you can see the colors in Special Edition are much richer. The image from classic Skyrim is on the left, and Special Edition is on the right. So, what you're seeing is me standing in the same spot at the same time of day with the same weather conditions in both games. The images below were taken using the same saved game, first taking a screenshot in the original Skyrim, saving the game there, then transferring the save file to Skyrim Special Edition and loading it.
Finally, let's take a gander at how the Special Edition actually looks.