First, it replaces all the low resolution character textures with better quality ones. If you want better textures and generally better appearance without straying away, Windsong is the perfect mod for that task. I'll start with the most vanilla-friendly.
I cover a range of mods, from very vanilla friendly to all the way glamorous. In this article, I have a list of 10 mods that alter character appearances for the better. Thanks to the power of mods, nothing is ever set in stone. But a combination of generic face models and low textures made the NPC appearances unimpressive and forgettable. They can, if that’s what the developers want. I’m not saying characters have to look like supermodels. While Skyrim’s NPCs never looked as horrendous as that, we were still left wanting. We all remember the potato-faces from the Oblivion-era.
Bethesda was never particularly good at it. Character appearances, on the other hand, were already out of date. When Skyrim came out in 2011, it was a beautiful game with a lot going on.