  Egwene's ring interaction, everything we learn about dream bubbles and the GOI, and Rand's odd trip through the Portal Stone to Toman Head are three large signs hanging over the Arches telling us that the Acceptatron experience is a T'A'R/MW/Dream Bubble mix.  I don't see how the Portal Stone trip to Falme reveals anything about the arches. Everything the arches do can be explained by the properties of T'A'R (the subset known as "Dream Bubbles.") There is no need to access Mirror Worlds to build a scenario from a candidate's subconscious.  