This means one of two things.
That’s a ring around Chris’s neck. And it’s Jill’s. Or it’s a wedding/engagement ring that doesn’t fit for whatever reason. Or he doesn’t want to risk it falling off/getting lost, so it’s around his neck. It’s gotta mean something if it’s so blatantly shown. There’s something going on, and it better not be that they killed Jill off-screen (AGAIN). And I’m pretty sure he doesn’t wear jewelry in other games in the official costumes, so it has to be something. And the audio for the clip was cut. There has to be a reason for that too, other than ‘There is no audio for the clip.’ Chris and Piers may have been talking about Jill and it would’ve been a spoiler at E3 if the audio was played. :/
Either that, or it’s a memento from Claire. I’d be fine with this too, I guess (I hope she’s okay!), but I’m leaning more toward option one. Can’t wait to see who they reveal for Comic Con! (JILL JILL FREAKING JILL PLEASE?! But knowing Capcom, if she’s going to be revealed, it’ll be last.)
(It’s been a long time since I’ve hopped into the RE speculation ring! I love it, and can’t wait for more info!)