Is photography luck? I would say at least 50% absolutely. But you make your luck by anticipation, experience, knowing your gear, empathy with the circumstances you find yourself in and understanding the people that surround you by being in synch with the energy of the moment. For me at least photography is a spiritual connection.. call it Zen perhaps? The whole point of Zen practice is to become fully aware, here and now. This shot is nothing more than a happy accident. Had the boy remained still I would have been happy still.. but to move and create movement blur connects him to his elders and for me becomes an image that has more impact because of him. What does the portrait mean to you? Well only you have that answer..