I'm watching it with no sound due to other people, but it looks like they deliberately tried to capture modern elements in the background. Why?
Same here (no sound) but I expect it's a kind of art, to show what the pretend past of a reenactment looks like when photographed with a period medium. The goal isn't to duplicate the past but to record the reenactment. (Edited to add: didn't see Waterloo50's reply till I posted.)
On a side note, I used to have a camera like that, or an equivalent look alike. Mine was a "PonyPremo," 5x7, used sheet film but one could use any sort of plateholders for glass or whatever. It was from the turn of the 20th century and his is probably about the same era.
He's either got a different lens or it was a different brand, because the Pony Premo had a quirky double cylinder shutter. Still, his has a shutter, unlike most period cameras. You can see him press down on it in the first sequence showing him and his camera.
I always found that the way the camera was mounted, with the lens far out from the tripod support, meant that anything with a slow shutter speed blurred, and I needed to use a bulb and tube to trip the shutter. No idea how he's managing the longer exposures of wetplate with the shutter.
He's not pretending to reenact though, just a modern guy in modern clothes with a view camera, and those turn of the century cameras are great for that, cheap (relatively speaking), few moving parts. I bought mine just for modern photography.