There are restrictions on nudity even when alone. For instance, Haredim mention that in the toilet a Jew should “expose a little and cover up even more”; an oft-quoted story is told of an exemplary character from the period of the Mishna: “Throughout his whole life he never saw the sign of his covenant with God [his circumcised penis]”.
Written By Prof. Gideon Aran
Given the importance attributed to the issue, one might reach an intriguing hypothesis: namely, that exposing the male body to members of the same sex is less potentially explosive than revealing it to oneself. Haredim know that according to the Kabbalah the male organ is “God’s magic seal”, comprised of the letters of His explicit name. It follows that the Haredi can experience the emanation of God when looking at his own penis. This might be a source both of abhorrence of one’s own nudity, and its irresistible attraction.
Haredim refuse to acknowledge the existence of the body even by glancing at it. There are sanctions against touching, stroking, feeling or scratching parts of the body, as well as against looking at it. This refers to closely examining the clothed body; even more so the naked one. Indirect evidence of this can be found in the Haredi attitude to mirrors. Haredim do not hang mirrors in public spaces, such as shops, let alone yeshivas, nor in private houses (even in the bathroom).
There is no explicit prohibition on looking in a mirror, but there is a collection of beliefs and traditions that discourage it, such as the link between mirrors and the character of Lilith, an early Jewish version of a female devil taken from the mystical world of demons. Mirrors are seen as alive, possessing power and agency. When looking in a mirror, one is more seen than seeing. Haredim warn their children: “Don’t let the mirror peep at your body”.
Taken from “Denial Does Not Make The Haredi Body Go Away Ethnography of a Disappearing (?) Jewish Phenomenon”, By Gideon Aran.