front/end is easy, the nuggets just bump in to each other. Sides I guess are done by having more elasticity where the corners shall be. This way the filled tube

front/end is easy, the nuggets just bump in to each other. Sides I guess are done by having more elasticity where the corners shall be. This way the filled tube naturally expands to be square. I now think I know the how, but why? They stack it? You could stack cylinder shapes...