In these clips from that video, you can see that Jay Leno can just rest his arm at shoulder height at the very back of the Cybertruck. In the next instant Franz starts to open the vault and in the wider shot you can see by the clearance that the truck has probably already been lowered to its lowest height. I think the only spot to comfortably load the truck will be from the very back.
New trucks may be higher but perhaps people aren't using those for work. My truck is probably low compared to other 4x4s but I wouldn't want it any higher to actually use it for something.
Your video snapshot at 0.54 is of Jay standing at end of the Cybertruck (behind the tailgate). The snapshot is a couple seconds too late. That snapshot is later than the point I described where Jay was on the side of the truck and where he first put's his arm up on the vault. Jay put his whole arm up on the vault at .051-0.52 while still at the wheel well (at about 1/3 point of sail panel). Later Jay walked behind the Cybertruck.
They are moving fairly fast in the video.
To see the action better:
Set the video resolution up to 1080p HD, full-screen the video, turn the speed down to .25 speed, then play time points 0.49 - 0.52.