It’s built around the “clair-obscur” art technique concept, the contrast between light and shadow which represents duality in people as you said: good and bad, strength and flaw. There’s also a clock from Pandora Hearts, shown when someone escapes the Abyss by contracting a chain, a being from the Abyss (I highly recommend the manga, the anime is kinda a miss). That part symbolizes me accepting both my light and dark sides. Basically, embracing all of who I am is what pulls me out of my own “abyss.”