odf skin has high mattetranslucency. Snarly skin has SSS...none are perfected yet. For instance, we still don't have a good material for eyeballs yet, which I would think would need to be a homogenous scattering material (think milk). Only some of us fiddle with Luxrender materials and none of us are experts yet...lol. If you're a Blender user, you might want to try LuxBlend - those materials work in Luxrender as well. But in order to be used with the exporter, they'd need to be set up in a .xml document first.

I'm not sure you can necessarily make that portrait look better in Luxrender at the moment.

Laurie