I visited the exhibition "Japan Drone 2019", which was held at Makuhari Messe near Tokyo a few weeks ago. There was an idea sketch (photo above) that was made of cardboard, and it impressed me the most of all the things I saw at the exhibition.
I saw this amusing model at a booth of a company that develops their own original drones and robots. The model reminded me of the times when I made a model with carboard like this in my junior high school. In an art craft class, I had to make a wooden moving toy and I thought a lot about how to make it.
Drone business is already in a phase of industry, and various systems have been developed for transportation, construction, agriculture, disaster prevention, and so on. These are surely developed for practical use, but I think that the developers also enjoy working on developing them.
A smaller version of a mock-up made based on the idea sketch (in the first photo). This is not a drone (UAV) but it's a kind of flying bike that people can ride on.
There were a lot of aircrafts full of handmade looking.
The main venue of "Japan Drone 2019"