They probably knew in advance that AOC wasn’t going to endorse Biden, which is why they only gave her 60 seconds.
I say this because in the set up of speakers Joe's not positioned with anyone, yet Obama will stand with Kamala for VP....He's off at the end standing alone? Additionally Joe's video speaking with people, like Hanks, isn't addressing polices he's just rattling off and reminiscing about the days with Obama.
At any rate don't be surprised if this worm of a convention doesn't turn a whole lot.