How a height-increasing mirror works
A height-increasing mirror does not add real height. The visual trick is usually a mix of vertical stretch, slight width compression, and a camera or eye line that frames the body from a more flattering angle. When the body outline becomes a little narrower and longer, the brain reads the same person as taller.
In the simulator, compare Taller and Slimmer with the original photo. Watch the shoulders, waist, legs, and floor line instead of only checking the top of the head. Those small reference points show whether the body is genuinely reading taller or just cropped differently.