This picture brings across the message of friendship and something even deeper than that with the trio starting together and ending together. The idea is that even when something indestructible (Hogwarts) falls, their friendship will still stand.
Maggie Smith shot the last three HP movies while undergoing chemotherapy for breast cancer. She said she wouldn't allow it to beat her, and she was going to see the project through because it was one of her favorites in her career of acting. What an inspiration to us all