[imadr]

Yes, in rendering when we talk about “diffuse” reflection we implicitly mean fuzzy reflections due to light penetrating the material and exiting a small distance away from the entry point (less than a pixel far)

The term subsurface scattering is used for light that exits further away (more than a pixel) like in simulations of human skin

However that part of the article isn’t clear enough and warrants a rewrite