The image in the mirror appears to have reversed chirality. Reversed chirality is simply that, it doesn't have a preferential direction of horizontal or vertica

The image in the mirror appears to have reversed chirality. Reversed chirality is simply that, it doesn't have a preferential direction of horizontal or vertical. But our environment has a preferential direction in that we orient ourselves with respect to the Earth's surface, and the horizon is, well, horizontal. Our body is constructed with vertical bilateral symmetry which means our "halves" are horizontally oriented when in a normal standing or sitting position. All of this causes us to perceive and define reversed chirality in terms of handedness, left or right. Things that we perceive with a left-to-right orientation appear as right-to-left if chirally reversed. If we were spherical beings with limbs and eyes poking out at various angles from our bodies, living in microgravity on a space vessel, we would just perceive the reversed chirality in our mirrors as "enantiomorphic" and not assign a spurious L/R directionality to it.