Of course, you don't HAVE to play it that way.
Seriously, though, they use these stupid models every time they try to promote games with Eyetoy support. Its just a simulated image and gives no idea how it will look on screen, plus not everybody looks like a GAP commercial reject. Oh well. :\
But it looks like even if you don't like DDR very much there are going to be a few mini-games thrown in that have nothing to do with DDR whatsoever (but utilized the pad anyway), so there ya go.