These are beautiful pictures. What strikes me is their feeling of spontaneity or candidness, given these are from glass plate negatives, an inherently slower process of picture-taking than the smaller format cameras. Funny though, the 20th century was the century of the small format camera, and yet it took a while for people to “think” small format. Hence, you have countless snapshots, an ocean of them, in which people pose lifelessly, rigidly in front of the camera just as they did by necessity in front of view cameras a century before.
What is pathetic a lot of people looking at Victorian/Edwardian photos think these people were dour because of the facial expression but as you point out you had to make a comfortable facial expression you could hold or else the photo was ruined.