When you move around the corner like this, the last in line suddenly has to move around the corner really fast to stay in line....or they get thrown off.
It's an old game for schoolchildren. They all hold hands and run really fast single file. When they decide to "crack the whip" one or more kids at the end need to hold on tight or fall off.
It's mostly banned in schools today because the kids who fall off the end often ended up injured.
When I was in highschool around 30 teens decided to do it. First crack, three teens who came off the end. One had a broke wrist, the second a sprained ankle, and the third broke 2 ribs.
Larson is layering a turn of the phrase: ‘crack the whip’…which means: to use power or authority to make a person or group work harder or behave in a disciplined way.
The dogs taking over control is part of the joke. Another part is if you look at the dogsled chain as a whip and were to ‘crack it’ like an actual whip, that would send the musher (authority figure) into the water…and thus breaking the chain of your oppressor.