That is just bad manners. Plain and simple. She obviously thinks its 'cute' or a 'quirk'I know Mukbangs became a thing about talking while you eat... but with your mouth rammed full and wide open?!
You know how some Youtubers burp on camera as their 'thing', maybe she thinks seeing her mouth crammed with food is good viewing.
Oh and if she then moans how broke she is, yet has enough for that take away, I will scream.