The answer to why it has no jaggies and why the gun is cut off is simple, its a scan..
Regarding the second screen. In that shot the second screen is clearly being used for weapon selection, view selection (night vision ect) and camera view. But that doesn't mean that's all its used for. Apparently it will also be used for movement, various mini puzzles/games (lock picking ect) and aiming. While I don't actually like using the touch screen for movement in Mario 64 DS I think it will be great for Splinter Cell. Since its more about sneaking then running around.