It means it's a diffuse(for example mid-grey)render pass, an AO render pass and a reflection render pass composited together. It's what's commonly called a 'Clay Render', which in this case also has reflections. The shader could also be created directly and output as a single beauty render pass - which negates the need to…
I noticed that too, compared to my attempts it doesn't have that "dirty" shading around switches and knobs, just more of a soft directional light. I was really surprised that AO could *almost* pull off directional shadows, but it's not quite the same. The more I increase the max distance for AO, the more it resembles a…