Try to find the spot where the photographer was standing.
What do you think those things along the top of the frame, on the wall, are? Something related to the glass plates the photographer used?
[https://www.flickr.com/photos/katdalton] Just framed photos Acsinte displayed in his studio. Probably the bride and groom didn't want strangers in their photos and asked those frames to be hidden/flipped.
[https://www.flickr.com/photos/costicaacsinte/] Oh, I see. But then that fellow on the top left snuck into the photo :)
I notice that in a lot of Acsinte's outdoor portraits, there will be actual people in the background...someone looking over a fence, through a window, or just standing nearby. Fascinating to see these "accidental" portraits.
This entire project you are doing is fascinating.