Do you remember Oskit in the spanish forum?

[AJLynn]

I suspected Photoshop but I was able to replicate some of the stuff in beta that made me suspicious. E.g., the scene in a hallway with light through windows making caustics that are reflected in a mirror - this actually works in beta, though very slowly, if instead of sun you use extremely large emitter objects just outside the windows. The renders they labelled as V1 could have been done on one of their unstable and feature-stripped internal versions of "RS1+" if they had different builds optimized to perform specific functions.