It's called a ball joint flip on other pages... You undo the ball joint bolts, and move the ball joint to be positioned underneath the arm, rather than on top of it. It moves the top arm upwards, so you can gain more downtravel. It's not a lot, but every bit helps.
By doing this, you gain in downtravel, the width of the arm and the width of the ball joint itself. You can see in the pic below he may have gained an inch or so... depends on type of car.
A lot of 4runners in the US use ball joint spacers and you can go any size you like. They install these between the arm and the ball joint to drop it even further down.
It just moves the top arm up out of the road, as hitting the top bumpstop is the first thing mainly to stop flex.
I'm thinkin of doing this along with some front diff spacers.. to get my CV angles back down.
P.S - P!ss off F70
This is off an Isuzu forum... but same principal...
BEFORE
AFTER
