Torn cable on a phone I bought, unsure of what it's for.

Hey, I bought a 6s plus of someone and after looking inside my boss pointed out I had a torn ground. I thought it may have been the camera but I'm finding it's something else.

I'm not sure what it's for exactly so I decided to ask on here!

It appears to be a little bit above and to the right of where the back camera flex plugs into the connector. I unscrewed the screw and the little piece came off that you see in the images.

https://imgur.com/a/O2nI0

Anybody know what this is for?

Thanks :)