The song "Portrait Day" from My Little Pony is all about the bond between friends and the special moments shared together. The lyrics talk about being there for each other through thick and thin, and how even though they may be different, they still support and uplift each other. The song celebrates the idea of friendship and the joy of having someone by your side as you navigate through life's ups and downs. The catchy tune and uplifting lyrics capture the essence of friendship and the importance of having someone to lean on.