How about a nice plant.

I don't think anything is missing, but I do think the two chairs look like an afterthought. Could you bring them in closer to the sofa, or even put one on either side of the sofa? And while your throw pillows are nice, where do people sit? I would lose two pillows and the throw, personally.

Looks good to me but do not like the throw in that spot

I'd put there some plant to make it more lively.. on the right of the couch maybe ?

It looks good to me! Warm, comfortable and inviting. I do agree about the throw though, you may want to move it to the arm of the sofa

looks great change the décor you have on the corner for a larger plant that will fill more the space. No to close to the window wall, closer to the sofa.

I think I would move the two chairs at the window in a little. Further from the window and closer to the couch.

Bring the chairs up to edge of rug. I would consider sewing a cording or patterned binding. 2-3 inches around drapes This is a very nice color scheme that allows you to move the furniture freely.

Have you tried putting that great mirror in the window corner?

I think that the amount of red walls are throwing this off...the shade of the tan wall competes with the red..it appears to have a pink undertone instead of gray....yes, many shades of red out there just to drive us batty.. I would repaint the red walls and paint the smaller wall a deeper red.....and I'll bet you just painted the wall red didn't you? oops...probably not what you wanted to hear.

Do you notice the picture over the couch? What stands out most? The black frame or the red flowers (subject matter) I think the black frame stands out more and the subject matter gets lost...point being...is that the black is the contrast and the red item doesn't Its a balancing act..contrast and blend...

the large vase in the other room next to the mirror would look nice in this room ...try a corner next to the couch and the small wall? or move the twigs and place them to the right of the couch. Perhaps the mirror hung sideways will look good....just try it...
I would pull the chairs in closer to the table or if you have room place them across from the couch closer to the table. Does it make a difference?

Also the rug doesn't HAVE to be under the couch...you can have floor space between the couch maybe two feet...by spreading this area out a bit it can give the illusion of a larger area..
Keep only 2 pillows on the couch..stack the others under the coffee table for kids to use as chairs? Why not? or stack them in a basket by the to bring the color to another part of the room.

i do hope this helps

The first thing that caught my eye was the placement of the chairs. They need to be closer in and brought forward if there is space. One appears to be further back in the corner than the arm of the sofa. If you can't bring them both out more I would put one on each side - maybe angled in near the corners of the rug.
While the twigs do provide some height they blend in with the red wall and the clear vase has no presence. I would either try a tall plant in a nice pot or try putting the twigs in the vase on the opposite wall.
I agree that there are too many pillows on the sofa. I would loose the red ones and change the placement of the throw.