Fabulous minimalist home. I'd remove the short columns with the light fixtures. They detract from the entrance door. I'd place large lighting fixtures on the wall on both sides of the door and down on the wall near the third large column. Remove rounded plants in front planter. Use wispy clumps of decorative grasses. Plant aloe or low clumps of decorative grasses along entrance walk. Remove shrubs in yard. Taller cactus or palms fronted by agave off to the right and left of house. It's not just a low box.

The tv seems awfully big for the fireplace and looks "off". Would you consider putting the tv in one of the nooks instead? Admittedly, that's what I have. My tv is on a slight angle in the right nook and I have a low bookcase from Crate and Barrel (it was a scratched one, and the scratch is on the side so you don't even see it - got a great deal!) on the left. I have a vase will tall wood flowers on the bookcase. The bookcase and tv stand are both black so they coordinate. Sorry I don't have any pictures.

The additional pics are helpful. What is the switch on that wall? If not in use, I'd think of a larger piece of vertical art for the wall. Or perhaps I'd get matching curtains for the window. Functionally, you don't need anything in that spot so I wouldn't rush to find something. A plant in a nice planter could look nice. If you don't have a green thumb, look for something "sculptural" you find while treasure hunting. A child's antique or vintage chair? Maybe you have something in your home that could work. As for the coffee table, the current one looks to be a good size? If I found it too bulky visually, I'd consider glass or paint this one.

No to fixed shutters, and no to planter boxes - these will just draw the eye to the differences. I'd deal with the issue through landscape. A tall tree on the "short" window side, and lots of depth/texture/color/height variations on the front of the addition to give the eyes something else to catch the attention.