The song "Mirror's Song" by SBPCH talks about nostalgia and reminiscing about past relationships or connections. The lyrics describe moments when the world seems dark and cold, but the singer finds solace in memories of loved ones. The mirror is used as a metaphor for reflection and introspection, as the singer looks back on the beauty and warmth of those they miss. The song captures the bittersweet feeling of longing and the comfort found in memories, even when surrounded by darkness. It reflects on the power of love and connection to bring light and warmth to our lives, even in the coldest and loneliest times.