A normal mirror already does flip things vertically just as much as it does horizontally, which is to say not at all. This about your expectations of what a pe

A normal mirror already does flip things vertically just as much as it does horizontally, which is to say not at all. This about your expectations of what a person (or thing) facing you looks like. Normally when someone turns to face you they'll spin around while staying in a head-upward orientation. That puts your right hand and their right hand on opposite sides because they've spun around, while your reflection's right hand stays on the same side as your own because the mirror doesn't flip anything. If you instead expect the other person to turn to face you by doing a hand stand, then you can say "Why is my reflection's head on top?! It should be on the bottom! The mirror has flipped it vertically!"