This exercise refers to one of the animation principles, called Anticipation.
The ball Anticipates by Squashing against the springboard. This way it communicates to the audience and prepares for the next action which is the jump.
I am pretty happy with this animation, as the all creates a really nice arc when it jumps. That arc makes the jump more realistic and definitely not mechanical. The trembling of the springboard adds to the effectiveness of the whole animation but after I playblasted the animation, I noticed an issue with the ball. Before it jumps off the surface of the springboard, it goes through it a little.