clear mirror of hell; mirror in Enma's chamber that reflects one's deeds
Buddhist term: a mirror in the court of King Enma that shows the good and evil deeds of the deceased. Used in the context of judgment after death.
See also: 閻魔
It is said that before King Enma there is a clear mirror that reflects all of one's deeds in life.
閻魔 is the king of hell who judges the dead, while 浄玻璃の鏡 is the mirror used in his court to reveal the deceased's deeds.
From Buddhist cosmology; 浄玻璃 means 'pure crystal' and refers to the clarity of the mirror.