You should not laugh at this. It is wrong to make fun of someone for his or her physical shortcomings, no matter how fat they might be. Did we laugh at this when we first came across this video? You bet your ass we did that is why we are sharing it with you.
What amazes me is this girl laughs as she crashes through the trampoline. If I were in her chubby little shoes, this would be the breaking point that got me to the gym. The sad thing is something tells me jumping on the trampoline is the first exercise the girl has seen in awhile. An exercise session cut short by physics.