I would get a much larger rug, add a credenza under the TV and add some wood elements to the mix.

Also, here's a subtle way to add some color:

It looks lovely so far. I agree with a larger rug, it will open up the space. Also, give yourself some time. It takes time to collect things you like, don’t rush it. I’m still changing things around and adding things 6 months later.

Here is a different angle...how large should the rug be?

It's all about the balance and symmetry in the room. I would recommend to place your TV on the center of the right wall. Then to place the round mirror on the back wall where the TV is. Remove the round flower wall decor from the back wall.

Try turning the beige sofa (that is on the right side) with its back to the back wall (where TV is now). It will open up the space and will feel more open and inviting.

If you'll like it, then place the small gold end table to the right side of the sofa that is on the left side. Then remove the 2 large side chairs. Possibly consider to buy a larger rug and some nice window treatments.

Good Luck!

I agree about a larger rug, it should cover the entire seating area, ideally with a little extra margin. I also suggest that you add a small bright rug on the empty floor space, either with a striking modern pattern, or ethnic or an oriental rug. I I have seven lamps in my living room that is rather smaller than yours and I don't think they are too many. (I live in Sweden where we need light especially in winter.) I would add pictures, too, not necessarily paintings, some colored cushions and throws.

Agree with making the mirror wall the TV wall. Are you planning on any window treatments? You have a great base to start!

I don't think a larger rug is the issue here. It's VERY monochromatic. Plants add LIFE to a room. How about a potted plant/peace lily next to the chair.

Lovely space! I would add a larger rug, a warm wood cabinet under the TV, drapes on the windows (keep the rods up high), and pillows and other accessories with soft color rather than white. The added color can be soft rather than bright to maintain your calm cozy feel.

A much larger rug in a pattern with some color, including some gray, will give you a color palette. Select a few colors in the rug and add those colors to your room. No more gray!!! Too much of any one thing is too much! Your room is drowning in gray. Now you need the rug, several pieces of art with color, some non-gray painted furniture, colored accessories.

I think a few POPS of color would add the life your looking for. Pick a color you love and add pillows, art, throw, etc. Lots of good advice already, a shelf or something under the TV, a bigger rug, some pretty plants. its a great room!

Add some COLOR ! Also some soft sheers on the windows this will soften the look of the room.

All the colors are blending together. Need a color or two that stand out. Pick up some pillows in different colors to help you find the color family that works best. Then return those that don’t work and get more in the color family that works for pillows and blanks. Art with a little color is also an idea. If you do art you can pick a color or two from the art for pillows. Good luck as it really is a nice looking room.

Your rug could definitely be one size step bigger, but I am not sure that is the "problem with the room. I am usually a color person, but I do like the palette you have here. I am drawn to your credenza with the black and white art. I would use that as a jumping off point and add some more black accents to the room. A few black pillows for the couches and maybe a dark cabinet for under the TV. The below is a more modern space, but I really love how the dark pillows add contrast and depth to the space.

I think the seating area is too closed off to invite sitting there.
From the first photo it looks like you would need to leap over two chairs to sit on the sofa. The rug should be 9x12 for that size room. It will automatically show you where to place the furniture so that you can easily walk around it. You need more space around each piece.

Wow! That looks like some view out your windows! Probably adds color to the room in the daylight...is that right?

The focal point ( tv) could use reinforcing by facing the large sofa towards it and switching with the two chairs. The tv needs a console under it. Your home is exquisite.

like this room.

push back your sofa on the right a bit and find a sofa table to put between it and the wall. remove the mirror and find some killler art work w/some colors

bring in a wood console for under your tv.

Some camel leather poufs or chairs also warm it up a bit. maybe a couple of the x stools under the tv or off to the side

This blue is beautiful w/your grays. In fact, if you did one bold color like this console for under the tv, and brought in some nice art work, the room would look 10X better

do a white and walnut, mcm type of console, tall plant in the corner, maybe one of these chairs

I really like the idea of bold color enamel like this cobalt

Or, something like these,,

Flip the TV/mirror as suggested and then turn the seating arrangement 90 degrees, spreading it out on a much, much larger rug so all the seating can sit entirely on it since they are all leggy pieces. Add a credenza under the TV that is a minimum of 25% wider than the TV. IMO, the trio of flowers are more suited to a little girl's room. I'd like to see some white sheer drapery stacked back at the windows to add some visual warmth. Even though sheer, when closed at night it will cozy the space rather than have black windows.

I like the mirror where it is because it is reflecting light from the windows.

some other ideas. look at the window shades in this pic, and the white console.

Try these for your wall and windows

The rug is nice, orange throw, blue pillows and the artwork (it's hung too high though) all bring a little life to the party. The white console is perfect because it has the warm wood panels in the front.

Try getting some solar shades in black/white

https://www.overstock.com/Home-Garden/Chicology-Midnight-Black-Beaded-Chain-Solar-Roller-Shades/17432607/product.html

or maybe some roman or cellulars

pull all the furniture off the rug by about 10 more inches or so.

On the long wall, you could do something like this.

sofa would sit in front of it like this

Include ceiling molding.