On the 4th disc there is a guy who wore glasses like Jack.He was hiding with the binoculars and then blew everyone up .Then he shot the guy after.Who is that guy?I never seen him before.

His name is Alexis Drazen. Brother of Andre on the show. If you watched the episodes, it states he's the second hitter for trying to kill Palmer.

I have two questions:

1. Whatever happened to the guy who was impersonating the photographer?

2. Was it revealed during the first season for what organization Nina worked? If it's a season 2 spoiler, please warn or use spoiler tags before providing the answer.

1. That guy just kinda disappeared I suppose. Afterwards he wasn't relevant to the remainder of the day, so no need for anymore screen time.

2. Still don't know who she's with yet.