Gamers know that developers often put little Easter eggs into the games that are a challenge to find. These Easter eggs are often things like odd levels that you can play, like the infamous cow level in Diablo II. Halo 3 had its share of Easter eggs hidden away and one of them only works on a single day each year.
That single day of operation is the reason why it remained undiscovered for seven years. This particular Easter egg is only accessible on December 25 via the loading screen by hitting both thumb sticks. The result is that the screen zooms out giving a wider view of the Halo ring and a birthday greeting for Lauren.
The greeting reads, "Happy Birthday Lauren!" It's hard to believe that no one mentioned this Easter egg for all those years. I guess it's cool to have your own greeting in a game that no one knows about.