When most people think shipping container they are thinking a solid steel box used to transport goods around the world. A unit that is able to rust easily and overheats in the sun at the same time cold when temperatures drop.
In reality you have this on the left, a blank canvas for modular construction the box like shape gives you a starting point that has many alternatives in its construction and not only that its easy to work with. The skill set needed for self building is reduced drastically down to weights and possibilities, design is reduced down to budgets and creativity. So when you think container think of the drawing as its the basis of modular construction that is sustainable and often from re-cycled units allowing a reduction in waste at the same time putting it to good use. Also using the shape from the drawing takes away a lot of the boundaries people set in their mind and allows the thoughts to flow on how to attach multiple units together to form up a home. The important thing to remember though is the strength comes from the outer frame the wider parts shown on this side of the drawing.