Even looking at the graphic, I didn't understand --- I thought they wanted me to tilt my iPad along the horizontal axis (pitch). When that didn't work I tried tilting on vertical (roll). It wasn't until the tablet slipped in my hands enough to rotate sideways that I got a clue.
[1] http://i.imgur.com/lW3gZOw.jpg
Edit: Figured it out after actually looking at the graphic. You need to turn (not tilt) the device to landscape.