Hate to be picky anon, but robe should be rope, when talking about the pedestrian barrier.
There's definitely something that feels off with the video (including a lot of what you point out, high res' but low quality), but that may be by design to bait anons - always get that feeling with anything RBG related.
The security guy and the rope barrier - there is enough room for someone to walk in front of him - there's a few feet between guard and the pole of the barrier, which is fairly tight up against the coffin, imo.
If it is a deep fake, then it's professionally produced - look closely at her glasses when people walking behind etc. the lenses behave as expected.
I'd urge a bot of caution on this, as I think we are being baited.