My STS Lobo had the same chainstay as in the 1st pic. The one you showed looks more like the 2nd gen swingarm as it has the spot to mount the floating brake.
mine is a first gen, i believe. it has the skeletonized and angled chainstay with round tubing, and the heavily lightened rocker that attaches to the shock. and note the floating brake arm was mounted via clamp to the chainstay.