The light looks a bit too bright in the pics; it's adjustable so maybe they cranked it up for the photo session. They'd better because the text looks significantly lighter/grayer than the Kindle Touch next to it.
Also, I'm not sure but the STR has a white on gray night mode, right?
If so, that might help...
Oh, and the tech is reportedly B&N in-house, not a Flexlight light guide.
And they're filing a patent!
(It's a start.)