For she is a breath of the power of God,
and a pure emanation of the glory of the Almighty;
therefore nothing defiled gains entrance into her.
For she is a reflection of eternal light,
a spotless mirror of the working of God,
and an image of his goodness.
Wisdom 7 25-26
Speculum Justitiae or Mirror of Justice is a name given to Our Lady in the Litany of Loreto. From here:
“The various symbolic meanings of the mirror highlight: (1) purity of the soul, (2) self-knowledge and moral integrity, as well as (3) its ability to reflect reality. Mary’s soul is holy and pure. She reflects the Sun of Justice, meaning God’s perfection and holiness. She is the mirror without blemish of God’s majesty (Wisdom 7:6). […]
Thus Paul reminds us that “at present we see indistinctly as in a mirror, but then face to face” (1 Corinthians 13:12).”
Our Lady´s chapel in Altenmarkt. Fresco illustrating the Lauretan litany “Mary, you mirror of justice” Rights here.