These print outs show you the action in that 1 second
recorded as 21:51:31. At the top of this page I state that the
price of the ES dropped 6.50 points (0.6%) in one minute. If you
take the first traded price at 21:51:31 as 1094.75 and the low
during that second of 1089.00 then we see that the ES actually
dropped 5.75 points (0.53%) in one second.
(For your information, the red prices are where the ES is
being traded at the bid and the black prices are where it's being
traded inside the bid/offer.)
As all the bids at each price level are traded and the next
price down is touched it causes more stop loss orders to hit the
market causing a cascading effect.