I'm still waiting on my P6 shipment so I can only comment from my experience in P5. If you apply the skin node to just the face, the default Ka setting (ambient light?) reduces the darkness of shadows on that surface. Consequently, if there is a dark shadow running along the face to the neck and body, the shadow is SIGNIFICANTLY darker on surfaces without the skin node. This sometimes resulted in eyes, lips and teeth being unnaturely dark (compared to the skin) if there was a shadow across them. I either adjusted the Ka on the skin node or apply the skin node to all of the surfaces (eyes, lips, and teeth.) It looks like CL just fixed the skin node so that the shadow darkness matches across all surfaces, both with and without the skin node attached. In other words, they fixed it in P6. Just try adding another light shining in the front of the face, or turn up the Ka if you want to match P5 settings.