This is a pivotal scene from the Ramayan represents the moment where the humble Hanuman learns of his innate powers from the ever-wise Jambavan. He then grows to a giant size and readies himself to take a mighty leap towards Lanka as the vanaras cheer him on.
Often we find that we have a lot of hidden talents within ourselves that only a keen external eye can discern and point out. That is the whole point of having wise mentors or coaches around, not just to correct your mistakes but to also make you realize your true potential.
Lanka represents the goal, Sampati represents the identification of the goal, Hanuman represents the means to attain the goal and Jambavan is the identifier of the means to attain the goal. These four components together lead to goal fulfillment.