When the power cord stretches enough to pull the plug out, the coyote climbs out and finds himself vibrating sporadically. To "punish" the book, Wile E. walks over to it and prepares to tear it in half, but one of the vibrations does the job for him.
When the power cord extends beyond its capacity, the coyote climbs out and starts shaking. To "punish" the book, Wile E. plans to tear it in half but is interrupted by a shake that achieves his goal.