What is likely, from my experience, is that the people designing the case were given rough dimensions and were told "it's a PC".  So what you have here is a bunch of creative ideas/possibilities that have been generated by the case manufacturer and passed onto BA.  BA will then either choose one, or choose bits and pieces from all of them and then have more renders made.  Once the final design is approved, it gets signed off and sent to production.

Mind you, this is just my interpretation having done this type of work in the past.