Review Detail of imKioshii in Percy Jackson : A Gamer's Journey

Oh um, I was just wondering if you knew where the art from the cover came from? (Ex. Instagram, Facebook, Twitter) (This is just to fill in the characters, pls ignore: pihfasdjihougbjkqwfashuibhkjdhuebhkasjhueqbkjfahdubjkadfsbkas)