oh oh oh I saw it too, I'm in the club,
Caught it first time
The top image was sort of flashing on & off (but not animating). Scrolling the window made it flash faster. Trippy. I suppose I could have recorded it, but... meh, I probably should be doing some real work
exciting update:
Can't duplicate it though - going back to the same page doesn't make it happen again. awww