When you say the seams are inside out are you referring to the welting? if so it is the way it is supposed to be.

yes is it called welting? It looked like it was sewn inside out and I like the look of it. Do you know where I can purchas it?

I can't quite tell from the picture, but welting is fabric wrapped over a cord. It should be pretty much circular. They could also have something called french mattress seams, where there is no welt cord. You can see people making cushions with them here:
https://www.youtube.com/watch?v=p--9IaqIumE

It's a flange edge. The sectional is probably made by a north american manufacturer since the European companys tend to make the edge more pronounced. The closest to the style shown that I'm aware of is the G-Romano domino though the Verellen Wyatt isn't far off.

sometimes called a flat seam. Ask any manufacturer if they will offer this option.