I love the fact that just from this one trailer from the new Last of Us game there are already so many theories on why things are going on as the way they are in the trailer. And I've seen everything from fact that perhaps Joe is actually dead and we're just seeing some kind of hallucination inside Ellie's mind. To the fact that there's maybe a possibility that the virus has finally started to take its toll on her. This very well might be the reasoning behind her right hand shaking before she starts playing the guitar due to possible neurological damage. But at the same time we could also simply be the adrenaline wearing off. Only time will tell.