Skyrim Remastered has improved arts and effects, volumetric god rays, dynamic depth of field, and many more enhancements. In the video below, you can see how much the graphics differ from the original version:  

(Credit for video above: Bethesda Softworks)

Here are just some of the photos comparing the difference in the graphics but this time, footage not shown in the reveal trailer:

In the image above, you can see the difference in the face of Ulfric Stormcloak. The side on the right casts more of a shadow than the side on the left. Also, his clothes have a certain “depth” on the right than on the left (particularly at the center). And of course, the background. There is a difference in depth there.

Though the difference is hard to see at first, there is a greater distance aspect on the right image than on the left image. If you look all the way in the back, you can see more trees on the right image than on the opposite image. And generally speaking, the right side is lighter or more bright than the left side. Another thing to note is how there are more rocks scattered around the houses on the right image, as compared to the left image.

Finally, let’s see the difference between these two images. The right side is once again more bright than the left side. As a result, you can clearly make out the little details like the trees (especially those that are further away), the hill that they are standing on, and the tiles on the roofs. There is also a graphical difference in the aurora. The right one looks more smooth, as well as has colors of green and blue. The left aurora only has color of green.

These are just some of the graphical enhancements that Skyrim Remastered has. It’s also safe to say that the remastered version has more detail. But one thing that separates the remastered version from the original version is the light. All images on the right side are brighter, or have more light in them than those on the left side.