Infamous leaker, Steve Hemmerstoffer AKA @OnLeaks on Twitter posted a video of a CAD rendering he obtained
There's one issue with his CAD rendering and the legitimacy of it... he can't confirm that this is 100% accurate because Apple is testing several prototypes.
Last year, he posted a pic of an iPhone 7 case several months before the phone even launched. He gets inside info from the Chinese factories that build the phones.