Hold right trigger

what the hell is that vibration? is it just a normal interaction that we don't have access to in the demo? or might it be a way to interact with secrets in the demo?

i just finished my first play of the demo. it seemed like holding rt prompted different responses at different times. mainly, sometimes the whole controller would vibrate in response, and sometimes it wouldn't. sometimes the controller will continue vibrating for the duration i hold the trigger, sometimes it vibrates right at the beginning and then stops. sometimes it's more or less intense.

i didn't find anything in the demo that rt controlled even though i was hitting it all the time. has anyone noticed anything?