The bullet that grazed Trump’s ear has been analyzed to death as too close to be fatal from the gunman’s distance to reliably stage. There are numerous more plausible explanations than the one the video puts forward.

1. It is obvious that there might be good-looking photos if you take enough of them at any historical event. We already know that GOP campaigners cunningly used the assassination to their advantage for propaganda; the staffer is simply realizing that photos off the vent should be taken.
2. At the end it looks more like he’s telling the photographers to keep their distance and pulling them away from Trump. There is absolutely no way he can see the camera viewfinder from such a distance, which is needed to decide on how to adjust the framing as the video purports he’s doing.
3. The flag is simply being seen from a different angle. Throughout the video, the cameraman is approaching the gates, and then he tilts the camera upwards and then downwards. The former brings the flag into view and the latter is why the flag also looks like it’s being raised right after 0:36. Cross-reference the footage with https://www.youtube.com/live/Rr63RgGN-Yo?t=24263 (in both footage you see an agent go to the outermost. in the long livestream this is immediately followed by an agent waving Trump’s red cap.), a wide view, and the flag seems static.