Since the release of Roblox using the camera for these weird heads, new UI has been implemented. This new UI also has a ViewportFrame where you can view your character, but mirrored. How is this done?
Well, it seems like no one can answer this unsolvable question. But, not for the first time, I am here to reply to myself in the hope many others see this and think “What an awesome guy!”. I am probably getting my hopes up but who cares.
After browsing Roblox’s CoreGui in hopes of finding this troublesome piece of UI, I discovered that the ViewportFrame itself mirrors the view. And if you try duplicating it, it doesn’t show the effect anymore!
I thought to myself that this was some magic that CoreScripts were doing on a targeted ViewportFrame, but I was wrong. No, it’s actually a hidden, undocumented and Roblox-locked property called IsMirrored! Well, that is straight to the point. But at least I solved the topic. The next question is Who wants to create a post in #feature-requests:engine-features so that we have access to this property too?.