It’s a prototype. Surely easy access to the structure and equipment is a lot more valuable than nice seats and a finished-looking interior surface.

What does "usability" mean in the context of a prototype short haul passenger aircraft? It's got seats for people to sit in...

The competition in this market segment doesn't look like Middle Eastern airlines' first class cabin concept art, it looks like this: https://en.wikipedia.org/wiki/Saab_340#/media/File:Mesaba_Ai...