I’m guessing that either (a) the method of concrete extrusion or (b) the process the particular company uses doesn’t permit for what I’ve generally heard in the plastic 3D printing world called “bridging” — being able to create some limited degree of overhang to create arches. If you look at the building, there are no arches — the places with windows are gaps reaching to the roof in the 3D printed wall.

I’d think that one route to achieve that might be, during the printing process, sticking some kind of metal support above the window during the printing process, even if the extruded concrete alone doesn’t permit for it. But if they can’t do that as things stand, it’d explain why they might not want to have a lot of windows.