Previously, we had heard a bit about the character Michael, a middle-aged man who moved to Los Santos to retire but was drawn back into crime. In this newly released video, we learn a little more about him, but we are also introduced to Franklin, the young gangbanger trying rise up and leave that life, and Trevor, who appears to basically be a redneck psychopath.
Based on what little we're shown here, Franklin's story seems a little clichéd (if not a bit familiar), but in the last section we can see Trevor interacting with Michael and his family. Presumably these three characters don't have entirely separate stories, but rather their paths will cross over the course of the narrative. It should be interesting to see how it plays out.