Ostentatio genitalium (the display of the genitals) refers to disparate traditions in Renaissance visual culture of attributing formal, thematic, and theological significance to the penis of Jesus. That these images seem to have been created in good faith, with pious intentions, mystifies art historians, and many refuse to recognize the category as noteworthy or distinct from the nudity of angels and putti. Yet, as examples accrue, the conspicuous attention lent to Christ’s phallus cannot escape even the most disinterested gaze.
Source: Ostentatio Genitalium in Renaissance Art – The Public Domain Review