Rather than explain the effect you can see an example during the
following video; (17s-23s and another example where the titling is
behind parts of the scene at 1:03 - 1:09).
Fingers crossed that somebody can help!
http://www.engadget.com/2009/09/24/the-engadget-show-hands-on-with-times-square/
I seem to remember that they had similar titles in the Lost TV series
as well.