The self-portrait is a good way of articulating the inner self, as it allows the author to express poetic feelings, non-visual concepts or inexplicable states of mind using coded metaphors, and in so doing to liberated imagination and the unconscious mind from logic and reason. Through the facial expression and hand gesture depicted by the self-portrait, one can detect the hidden metaphors and unearth the psychological state of mind of the author.（Tung Ming-chin）