The Pictobox is the brand name of the actual invention: the camera. While the pictobox/camera is not a new concept and was invented tens of thousands of years prior, the technology was lost after the Great Flood, and then revived by the ancient Sheikah
10,000 years ago for the Sheikah Slate. The "inventor" of the new Pictobox just took the existing technology and the research that the Sheikah had uncovered about the pre-Flood camera and turned it into a marketable commodity. Before the camera, people had to rely on artistic ability. Afterward, however, a new fad took Hyrule by storm. Everyone wanted to get into the hot new thing that was photography, and taking pictures of anything and everything quickly became a Hyrulean pastime. The Pictobox was so fascinating and popular to the scientist/inventor and layman alike that it did not take long at all for the camera to become widely available on the market for the average middle-class commoner.
After the Great Flood, the technology of the camera was lost until the Ancient Sheikah rediscovered and revived it for the Hero's Sheikah Slate 10,000 years ago. The technology remained dormant ever since until the tail end of Calamity Ganon's 100-year-long occupation of Hyrule when a young Sheikah inventor by the name of Sorin Gykkakh rescued a book of old knowledge from a trash heap. Inside the book was nearly everything that Sorin needed to know about now about how camera technology worked, and while he could hardly make heads or tails of it, he spent the next few decades teaching himself about it. Unfortunately, he died before he could finish his work, but his son Simor was able to complete and then profit off of his father's work thanks to re-discovering the missing link that eluded his father all those years: film.
The Pictobox has become a household product for photography enthusiasts from many different walks of life. It is possible to get a decent, non-colorized Pictobox for around 60,000R, and a colorized one for 99,000R, both prices considered cheap for the average middle-class family. For those who do not have the money to own one, it is possible to rent one, which costs about 7,000R for 50 photographs.