If it sits in the kettle like it is sitting in the pics then it seems it would have to draw in wort from the bottom (or something*)...or else a lot of wort is gonna be left behind in the kettle.
* - we can only see one side, hard to tell what's on the other side.
Blichmann seem to put some thought into their designs so I would highly doubt that:
1. You're supposed to in any way 'load' it with hops.
2. Have to fish it out during the boil.
3. It leaves a lot of wort behind in the kettle.
That thing looks taller than the distance from the bottom of the kettle to the top of the dip tube, it has to have a slot/hole in the side.
It doesn't look like you could attach this to the dip tube prior to inserting the dip tube inside the kettle, and still get the whole assembly to rotate into place. So I'm guessing you have to install this piece similar to the way you install the false bottom, i.e. insert dip tube at angle, line up dip tube and the hole, rotate dip tube into place and lock it in. That is...IF this thing even utilizes the stock dip tube. Maybe it has it's own? EDIT: That was stupid. Who says you would need to 'rotate' it in any way...just shove it in. Durrrr.
But I still have no clue. I have a feeling if we could see the other side of it we could easily see how it worked.