It appears on this video they took a bit too much of the guts out of the container which has resulted in several reinforcements needing to be done. Firstly both ends have been cut out which removes the squaring affect similar to that you get on a flat pack wardrobe. Notice on a wardrobe once you remove the back section it wants to flop over? its the same issue. This is why cross bracing has had to be done to reinforce the container.
The other problem on this one is the roof section hasn’t got enough wall left in it as its been opened right up which has now had to have a roof section reinforcement as well as some upright pillars to support. Not a major issue but something you must build into your design.