Okay, so maybe this isn't actually a video of how quickly Mark feels the need to live every second of his life, including the bathroom breaks. But feel free to use this GIF for all sorts of fun purposes.
What actually happened here is that Webber's teammate in the #20 Porsche 919, Timo Bernhard, experienced a slow tire puncture, and thus decided to head for the pits (and thus a driver change) three laps early. As Webber had to be ready to jump in the car a lot sooner than he planned, he had to be fast about the whole thing:
Webber's Porsche was actually leading the race for quite some time until reliability issues forced the car to retire.
Better luck next time, guys.