How do you get gamer pictures on the xbox 360 without having live connections?

i was playing beatles rockband, and i got this gamer picture of the beatles rockband logo. i dont know how i got it just showed up one day.|||Sometimes games will unlock gamerpics or avatar items as you complete certain goals or achievements. You don't need Live to earn these. The latest firmware will actually put a "Gamerpic Unlocked" message when this happens.|||its special awards for playing the game, there are a few games that dew that, you can also get some from the discs that come with the Official Xbox Magazine