A sectional does take up more room than a sofa. You have much more flexibility in your room with a sofa and two chairs. How many people will use the room on a regular basis? 2? 4? more? Someone recently posted the recommended viewing distance required from the TV, let me see if I can find it. IIRC the distance should be 1.6 times the diagonal size of the TV. For example, if you have a 55 inch TV then the viewing distance should be 7 ft 4 inches approx. Found a chart: TV viewing distances chart That particular chart gives a range of 1.5x's to 2.5x's so you have lots of flexibility in your room. Also, I find rectangular rooms are a little easier to furnish than square rooms so you have an advantage there. Also the room in the insp pic appears larger because of the way the furniture is gathered around the media center and floating rather than lined up against the walls.

Here's a possibility. Move the piano left of the FP. Put the TV where the piano is now. It might sit on the low piece to the left of the single door, perhaps on a swivel base. Turn the sofa so its back is to the French doors and add a sofa table behind it. Place two small scale swivel chairs opposite the sofa. Adjust so all the seats are no more than 18" from the coffee table which should center on the firebox. Move the art from between the windows to 5" above the mantel. The other art may work flanking the French doors but needs to center 5' above the floor.

I love Yayagal's suggestion. It will be against the darker background of your sofa and look great

I think there are limited options in the space. Where the marketing plan has 2 chairs, what if you had one that looks like a ‘normal’ chair but swivels so you can face the tv? A projection TV can be a space saver too. It looks like you have a place to lounge the projector on th exterior wall across from the marketing tv. The person on the sofa could sit longways to watch. We had a similar set up once and it didn’t feel too sideways.