The White Room is a typical interior scene with a mix of textured glossy and diffuse materials that is easy to render for a unidirectional path tracer due to large light sources: the windows are modeled as diffuse area emitters. Since most light transport is governed by diffuse materials, radiance-based guiding techniques generally improve over unidirectional path tracing. At equal sample counts, noise is further reduced on glossy materials, such as the television and the reflections on the floor, by using our product-driven path guiding (NPG-Product). Primary-sample-space path-sampling techniques offer little to no benefit over unidirectional path tracing with our NPS slightly outperforming PSSPS [Guo et al. 2018] with an equal number of samples.