Additionally I would guess you May have some cracked leaves on the driver side. Possibly just that the springs are more saggy on the driver side. In each view (front and rear) you can see that the spring bushings on the driver side are lower than on the passenger side.
I'm sure the other folks who made comments are on the right track as well and this is more of an all of the above problem.
My sii had nearly an inch of lean and I corrected the problem using a half set of add a leaf's. I actually removed the bottom leaf on the drivers side packs and replaced them with the add a leafs. Still not perfect, but I can't see the remaining difference when I look at it.