2890 - Flip what?

Sticking with the theme of videos this week I found another interesting one. It asked the question, 'Why do things flip horizontally instead of vertically in a mirror?' It made me go 'WHAT?' I don't think I've ever heard this question asked before let alone thought about it. Well here's the answer....





And I triple checked the link this time. Of course that doesn't necessarily mean I caught ALL the typo errors.