In the universe of Ghost in the Shell, the name "Logikoma" comes from "logistics robot". Those robots are supposed to be a fast all-terrain vehicles for transporting weapons and ammo, basically. To do that, they need some storage space, and that's what the box on their backs is for.
I just finished making that box for Logicoma-kun. It's empty, and opens just like in the movie. It consists of several pieces of acrylic sheet, with paperclips for hinges, all hotglued together.
I might add some magnets there at some point, to make it snap in place better.