try posting the pix again... nothing to see

I see the pictures. How about just some large art? Don't get hung up on what it is if it's just for resale. There are a ton of large art pieces at thrift stores for very good prices.

I agree to add color, perhaps new covers for the pillows on the couch. I think that you would amp up the room with more light, perhaps a lamp either by the end of the stairway or between the two chairs.

The space with a tilting floor lamp looks crowded to me. Thin things out-the plant, side table and see how it looks I agree with something large on the wall

I think I'd snug the couch in to the wall, move out the floor lamp, put the plant by the window and spread out the chairs a bit to make the area seem more open. May not be a space for the glass table and also for what looks like a little wooden table along the staircase. You might not need to change out the art. It's a very inviting little space. Maybe add a throw to the couch? If you do try moving the couch and you like it, you could move the pic to center over the couch. I'd also move the small wooden piece off the stairway wall.

The piece of art in the first picture, the height would be about 6’. I don’t know if I could find a piece that tall.
Having it as tall as the window really looks good.
What else, 2 pieces?

===> Is this the main living room area?

Here are some quick things to try (some suggested above, too):

1- Remove plant, decor object hanging on staircase wall, all three pillows, the lamp, all the decor from the coffee table, the large squarish artwork over the sofa, and the glass end table. Take a photo from the front door.

2- Then move the sofa to the staircase wall and the two chairs to face it. Take another photo from the front door.

Post the photos, please.

I would move the plant to the window, pull floor lamp forward and scoot sofa towards staircase about 6-8 inches. Add more space between accent chairs so can enter the space more easily, and it opens it up more from entryway view. It’s lovely!

The sofa is too large for that spot - since it has to overlap the window, it is all the eye sees currently. Here's what I'd try. Remove the end table. Put the plant in the corner by the stairs. Try the sofa facing the stairs, and the two chairs opposite the sofa, near the stairs. Add a large piece of art as suggested by tozmo1. Then, try some smaller, lumbar accent pillows incorporating the colors of the artwork on the chairs, and a colorful throw folded over one end of the sofa for softness.

Depending on how much you want to spend, you can go with one piece or two. Not saying these are the right two pieces, just showing them for scale. I agree, move the end table out. I'd put the plant there. You have a coffee table, you don't need an end table also. Get a more interesting floor lamp but hard to say what that would be without seeing the rest of the space. Big wall dacor has a lot of options for big walls.

Artwork in the mock ups are starting to dwarf the space and look strange. Try the sofa on the staircase wall, the two chairs across with ample space between them and coffee table in the middle. The set up might nicely frame the space and your current wall art could be enough.

No lamp, no glass or other little side table, no plant. Remove the two big pillows on the ends of sofa.

Less is more when staging. You want people to feel the space is large and the less you put in it, the bigger it seems. Staging is not about decorating the space but rather framing it.

Can the chairs be turned so there's an open path into the seating area from the door? Either facing each other at each end of the sofa or at right angles to each other at the left side of the sofa?

The first thing I see is that the space is too small for what you have in it. Color is lacking and the furniture placement is off. It might be a good idea to play around with rearranging the furniture, but if you place a large painting on the wall, I would scoot the sofa over so it's centered under the art. Do away with the plant, and floor lamp. instead of a floor lamp, place a good size lamp on the glass end table and find a rug with some color in it so you can coordinate with throw pillows.

You need to clear out this room. Then one by one, piece by piece put only things back that sell the space as a living room. I don't think the lamp, the plant, the side table by the window, what ever is between the lamp and plant against the stairs wall, and possibly one of the chairs needs to return. Swap out a colorful pillow, fix the blinds so they don't appears broken and call it good. LESS LESS is more!!!

Remember, it's not what you need for your living space, or what pieces you want to keep, it's about making the space look large. You can always store your pieces and make do for a while.