Why do mirrors flip horizontally (but not vertically)?
Why the open web links it
Explains the optical illusion of mirrors flipping images horizontally but not vertically.
Linked by 11 independent sites, 3 of them widely read in the 2026-10 crawl of the open web, including dyndns.org, sciencealert.com, libretexts.org, laughingsquid.com, mikyab.net.
Cited in 1 Wikipedia article, including Mirror image.