This looks as though it was taken with a camera similar to my mom's old Kodak Brownie. 620 film, at about 2.42 inches square, is a large enough negative for fantastic detail. The pictures you used to get back from the lab were pretty small but really nice looking. I wonder if they just printed contact prints, without an enlarger.
Anyway, if you've looked at many Kodak Brownie prints, they have a definite texture and picture quality, and the dog in pants has it.