These look like stacks of small mattress, doesn’t it? But it’s basically a chair made from polyurethane cushions (the very type of material mattresses are made of back then).

From the Design Museum, a brief description of this work by Joe Colombo:

In 1967, he unveiled the Additional Living System consisting of moulded polyurethane cushions in six different sizes which could be pinned together in different configurations according to the users’ wishes. Two years later, he took self-assembly a step further in the Tube chair composed of four ready-made upholstered semi-rigid cylinders which, once again, could be put together into any shape the user desired. The final futuristic touch was the packaging. Colombo insisted that the cylinders of each Tube chair were sold “off-the-shelf” in a drawstring bag of his design.