This is either really cool or kind of creepy. I'm in the latter group, but you have to give BMW props for taking cinema advertising to a new and rather interesting space.
The technique used is similar to when one looks straight at the sun and then closes their eyes. Once eyes are closed, an image of the sun is captured as an afterimage. Don't believe it? Try it when the summer comes out in six months or look it up on Wikipedia (remember that site? The one that now sounds like WikiLeaks.)
BMW took the afterimage effect to a new place where they quickly flashed a bright light during an in cinema commercial and then the commercial asks the audience to close its eyes. Those who closed their eyes saw the afterimage of "BMW". It's a pretty cool idea; though, it isn't something that is easily portable as the projection of the logo requires a full installation behind the movie theater's screen. So scale is an issue.
Fortunately, we can all enjoy the concept via YouTube even if YouTube is unable to burn the BMW letters into our eyeballs. Maybe someday...