The photo is hung too high and it's too small. I would replace it with art that is 2/3 the length of the couch. Currently, the lounge feels sterile. Some items to consider adding are an area rug, coffee table, lamps and pillows.

I would get a coffee table, rug, side tables with lamps. Pick colors from your rug for accent pillows.

I like your modern furniture. I do feel the window treatments are more traditional than the furniture, so I would suggest switching those. Also, I agree with celerygirl that if you add a rug you can then use that to pick your accent color. For example a blue rug like below you could add blue accent pillows of the same color to your sofa. Good luck!

Rose Window Blue Rug, 9'x12' · More Info

Yes, the window treatment needs to go; I would keep just the sheers or you can have simple panels in a color that will go well with your new carpet or have them blend into the wall color. There is too much gray in this room. Break that up with art on the wall in lively colors, a large rug and colorful pillows. The all-gray look is a trend that has thankfully gone, and introducing both warm and cool colors in your rug, throw pillows and wall art will give this room some personality and complexity. You also need table lamps (overhead lighting is too harsh) on side tables and a coffee table. Add books and some tall plants near the windows and you'll have a welcoming and interesting room.

You have a fairly formal looking room that seems to be allocated to a more casual function.

It does, indeed, look a little cold. Your window treatments are quite formal.

One thing that I would suggest is that you bring your seating into a closer and tighter arrangement closer to the TV to create a more intimate space.

Your room seems big enough to create at least two tighter and more intimate areas by using the sofas in one area near the TV, and the chair and a small table with a lamp in another part of the room. Or, you might consider a small desk with a lamp, or whatever pleases you. Just do give it a lamp. Having it's own brightness will delineate the space. Personally, I would add that light and interest to that back wall where the chair is, since one wall has windows, one wall has the TV, but that wall behind the chair looks like dead space and could use some life. Those considerations might add some warmth to the room.

Right now it looks cold and cavernous. Even though the TV is a generous size, it still feels quite distant from the sofa, or the chair. The wall where the TV is has the feel of a large fireplace in a cold castle.

You might also consider warming up the floor with an area rug to help define the area.

it rather reminds me of some receiving room in the home of the lord of the manor. You are received in this rather formal room, asked to sit and wait on that distant sofa, framed by those formal windows, until you are greeted by the man who is in the rather official looking photo on the wall. The photo, itself, is informal in nature and seems to contrast with the formality of the window treatments. It looks as if even this photo would be to a better advantage if it were hung lower and in the context of a smaller and more intimate space.

In a more perfect world, I would get rid of the formal window treatments and throw in some color to the mix. The swagged valances hanging down in the window space have the effect of shortening the windows, and cutting them off at the top. A more pleasing line would be long panels of some color and pattern that grace the edges of the window and carry the eye up, or nothing at all but the sheers that add a nice softness. It has the overall sense of being cold and colorless and confusing in tone. Even though there are two good sized windows and the walls are light in color, it has the overall sense of cold and darkness and is not really inviting.

I really think that creating a little closeness and intimacy in the space would solve a lot this and dispel some of the coldness---plus some color and pattern.

I love me some brown color, but you could use some color patterned soft and scrunchy casual pillows on those sofas. You want the kind of pillows that you can scrunch up to get comfortable with, and not stiff and unyielding formal pillows that are like soft bricks, require dry cleaning, etc. You need some washable and scrunchy ones.

You seem to be aiming for a home theater type of room with all the speakers placed around the room. This might not be the perfect room for such. You might want to rethink your concept. It does not seem that two speakers sitting so close to the sofa and chair are well placed. You might hear the action very well, yet feel removed from the visual because you are so far from it. Your TV screen is not THAT big! You might appreciate it better if you were sitting closer and more intimately involved with it. This feeling of distance adds to the cold feel of the room.