What is the pattern or profile of the trim as i cannot tell from your photos?

I've updated the photos to show the casing and the frame molding on the walls in the dining room. Thank you.

What did the folks that designed this for you envision there? ... You could put mull cap (wide flat stock) between the units and only case the perimeter, but that would look better if those flanking windows were full length. The other obvious option is the back to back casing, but that looks kind of unnatural as well. One could maybe get a little creative under the windows as well. It looks like you are going for a paneled look on the wall with those "boxes" , something on a smaller scale could be done under these window to make this appear to be a full length, three paneled unit. In that case, once again I'd go back to mull caps that extend all the way down, casing that extends all the way down on the perimeter, and then some creativity in between

Flat square edge mullion covers between the window and door as HomeSealed states and casing for the perimeter.