At the end of the reach for the dead video, there are those two spheres that divide from the sun, while the original sphere looks like it's fading (dying?). At first I thought it was a reference to the trinity (yeah, I know, I know) but now seeing this, could it be that all of the twins are derived from the outliers (the "special" tracks) in form and/or structure?
I've also noticed in many of the tracks that themes that seem to follow each other either in unison or support and then suddenly change when one of the themes varies. I've thought a lot about how this (as well as other indicators such as how there are two separate "parts" to the songs, two columns of structure, seemingly two "sides" to the album, etc.) might be an insight to how the brothers are drifting apart. Constants are changing.
Beauty, eh?