This has been proposed before, but it was answered with resounding silence both times:

Is it possible to work some AJAX magic to expand the video summary of a video in the same way one can expand the comment section without leaving a video listing / the front page? A lot of videos have long descriptions that are worth reading, but clicking "more inside" or the video title introduces in my view unnecessary load times. It also allows for a more fluid sift experience to get as much information about each video as possible while minimizing the number of page loads.