1) characters have different big archetypical roles with visual hooks.
2) the game's roots are in dungeoneering - so visually exciting underground complexes like Moria or the Temple of Doom - but social interactions are things like a noble's costume ball, buying stuff from a merchant, or negotiating with a Thieves' Guild.
3) Like WoW the setting is "everything." You might encounter 1700s pirates, Ray Harryhausen monsters, Tolkien orcs, and Gothic vampires in the same game.