This is actually an issue on my LX holding my MacBook Pro here at work.
So I asked our Customer Care team if they had any tips. Here's what they said:
For that joint, we do not have an adjustment, but after a few times of rocking it back and forth it would get easier to move, same thing with the tilting (the 3rd picture with the 70 & 5 degree angles), what we’ve seen is that just comes very tight from factory (it might be the paint that sticks to pieces together), so it takes a few times to push them back and forth to make it easier to move on those 2 directions.
So give that a try, and let us know how it turns out!