Looking at the source, I think it's just a bug, it's the highlight overlays of the three panels in the "learn more" section that appear to grow over the whole content. Maybe someone didn't check for compatibility with all the old article formats when doing a redesign?
-
This Tweet is unavailable.
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.