The addition of a light box effect in a website has many uses. The first of which is the efficient use of space. I cannot say how many times there has been an overlap of visual content over a main area. The use of a light box deals with that efficiently in a manner that is pleasing to the eye. The other use of a light box is allowing the user to choose what exactly they want to view.
In the same div tag, one can toggle a photo gallery, a video clip, a swf. file and several other options. In the example that i have seen for the advertising of the movie “50/50” there is the option of viewing one of three files form the dock. The interactivity of this option is something that I will not overlook in the future.