Hmm, I am not sure, I took this photo on the Modern Atlanta tour about 8 years ago, but this project was by TaC Studios. I'll check with them and see if they can let us know.

Hi lindylee, architect Jose Tavel got right back to me - it's more complicated than picking up pavers, but here is what they did:

These are poured concrete "steps".
There are slate chips around the perimeter.
Mondo grass is planted between the steps.

Actually, depending on the area and slope, you could do it pretty easily using standard pavers.
First, grade the area.
Second, set perimeter boards (i.e. 5/4 x 6) in the desired shape (plan ahead to set the board to work with even paver distances).
Third, place sand/paver base and tamp down well.
Fourth, set pavers with edges touching each other; tamp down
Fifth, use a matching colored Sika pavement caulk and seal the joints. The caulk will be very viscous, so rather than try and fill each entire crack completely, go over all the joints with a thin bead, it will drip into the base of the pavers where they set on the paver base. After it cures, additional caulk fillings will top out the joint to flush with paver tops.