It looks like a burned DVD-R.
If you open up your movie case, don't get surprised by its design. And, of course, you shouldn't worry, as you didn't get a pirate copy.
This is a very cool move by Sony. The official 'Girl With the Dragon Tattoo' disc art design for the DVD, makes it appear to be a pirate copy:
See it by yourself (bigger pic):
NEWS SOURCE #1: Dragon tattoo has unique DVD design (via) MWT New And Views
NEWS SOURCE #2: Sony Pirates itself with Girl with Dragon Tattoo (via) BoingBoing
Our thanks to 'Gauss' for posting this news tip, it takes me back to the days of pirated PSX discs!