Lin Po-ting explains, "Usually later people imitated the Sung paintings with great skill, but they had not been through the process of observation, so they could often unwittingly reveal their weak points."
林柏亭解釋賞鳥對從事美術史研究的助益何在：「通常後人臨摩宋畫惟妙惟肖，但並未經過觀察，常會不經意地露出破綻。」