Move camera close to ground w/ HDRI?

Tojiro

So I'm trying to work with HDRIs now and I'm finding that they're working out great as long as I have my camera at or around eye level.  I recently came across this picture below as part of an HDRI set that has the camera really close to ground level.  Now when I move the camera the HDRI background moves with me and the view stays the same...  How do I set it so that the camera can get close to the ground like that?  The ground she's sitting on is (I'm pretty sure) part of the HDRI image itself...

EDIT:  Never mind, I just went and bought it and it's a finite sphere w/ ground, whereas earlier I'd been using just plain HDRIs.  So I guess that solves that.