The pen does indeed extend the nib out by twisting part of the barrel. What the description means is that, as you twist the barrel and the nib extends, the clip itself 'descends' to be more flush with the pen, so as not to be as obtrusive when you go to write with it (because your fingers will be right up against the clip). It's a very subtle effect--the clip only lowers a little, but it's still really cool.