It resizes the height of the "hero" element (the iPad mini promo at this time) so that it takes up the whole height of the browser window, pushing the footer below the fold.
I do suspect that this is nefarious because the US version of the front page does not exhibit the same behavior -- i.e. disabling javascript does not move elements (and thus, the judgement) up and down the screen at all, nor does it resize the iPad mini image.