Impactist has a blog post on how they executed their title sequence, and had this to say about the blur effect…
“Several concepts were explored with the final look being a photographic reinterpretation of imagery. We used unique and novel lensing techniques to recapture live action series footage and additional US Supreme Court location photography. Custom intermediate lenses crafted of polycarbonate and acrylic were created and combined with fast aperture primes to reinterpret and reframe sequences to be further manipulated via compositing and editing.”
So it looks to me like they might have photographed the photographs, and used analog lens techniques to achieve that creamy, wonderful blur effect.
So my answer (without being flippant) is that they seem to have done it for real. Now, the recipe for recreating that in AE is another story, but I would imagine you could find organic stock footage or video, to get from white to black in interesting ways, and then use those as masks and time ramps on adjustment layers to drive nice blurs like lens/camera blur, or Frischluft’s Lenscare (if those still work with CC?).
Okay that’s all I’ve got!
…ryan