The Zero object was a Kodak Brownie dating back to early photography, the camera itself originates from Canadia and dates from 1921. It's the mechanical process of taking an image with this camera that is removed from the usual process. There is no auto-focus or standard focus as we know it. A good judge of distance or a tape measure is useful. Instantaneous images that we are so used to with our phones is removed and the magic of processing the image with chemicals begins.
I inherited a camera recently, from one of my grandfathers friends, Dr. Doug a retired Industrial Glass Lecturer from Sunderland University. Dr. Doug had trained with my grandfather at University. My grandfather was himself a photographer, who enjoyed this process of working with light and revealing what he had taken, through this chemical process. He was himself a chemical engineer, who understood the chemical and physical reaction of the photography process. I even found out that my grandfather had converted a 60's caravan into a mobile darkroom in the Lake District during his earlier years.
I would often hear stories of him banishing his daughters from the bathroom for hours, when he was processing his images, and would leave them in the bath to render through. He would work in there for hours processing each negative through a process of precise chemical mixing, timing and using the physics of light to develop his pictures. Light, was not just part of the process when taking the image, but it was the whole part of the workflow.