The implication of having short legs can be viewed here perfectly. See how a group of penguins try to overcome this tricky obstacle. At the end, life is about overcoming obstacles and challenges.
Watch how the penguins realize this metaphor one by one. Only after the bravest penguin managed to gather all his courage to overcome this obstacle, the others followed.
However, one can also change the perspective and perceive this video as an example how minor changes of the natural environment can affect animals. Even though this instance might seem funny, there are many examples, which are not funny. Nevertheless, enjoy the video!