They used to do things like that a lot back in the days (game-play videos, not CGIs, obviously) if you left the game at the main menu for a while, curiously self-recorded game-play videos of devs is a long gone trend, not sure exactly what triggered its disappearance over time. I recall that rarely some games had multiple videos like that, and that some of them sometimes revealed some easter eggs or secrets that the player would have otherwise missed, especially for combat games like the Mortal Kombat series for instance.
As for Mass Effect 2, the CGI video was revealed in regular media prior to the game's release, but it's nice to know that they left it in the game itself.
