Concerning the Nokia Lumia 920 and "volume thickness"

Because I'm an anorak, ever since the Lumia 920 was leaked, I've been trying to work out how thick it was. My concern was ergonomics, and how well the phone would fit in hand. Eventually the whole specs were put on the Nokia website after the announcement, but I noticed something: it was 10.7mm "volume thickness". I first thought that this meant at it's thickest point, but I realised this didn't make sense. What would make sense, would be for it to mean the thickness if the back was equalised and flattened, while keeping the same volume. This would make it considerably more chunky than competitors at this screen size, and makes me worry that this phone is gonna be too much for many people to handle (especially with the weight).

Can anyone confirm whether I am right?