It's applying higher voltages than required to get a faster switch.
If you want a RL example, it's like your Boss trying to get you to go to work faster by telling you you'll be fired if you don't arrive at work in 10 minutes. It's aplying more pressure than is needed to achieve a faster switch. Now here's the second part.
once the apropriate level has been reached, it automatically switches to normal pressure to get it to stabilize at that color.
A RL example of that would be your boss saying (Continuing from the above example) "You're 40 seconds late, but what the hell, I won't fire you."
This cuts the response time in more than a half. Which is pretty awesome. I mean, they were talking about 15MS response times.