Little confused, since you show three different arrangements, but I guess the first picture posted is the final arrangement? Looks nice!

Oh wow! so calm and welcoming.

In the top photo it still looks like the chair is blocking the entrance to the seating area. i like the open access with the table on that back wall.

Just offhand the thing that strikes me is there isn't any kind of focal point in your room. Also, since your room is rather small I think you could lose the desk and move your chairs so that the grouping doesn't seem so crowded. Good luck!

Getting better, but the clear desk needs to find a new home. It becomes the focal point because it is such a contrast to the other furnishings. Position the chairs opposite the sofa with one of the round tables between them. Floor lamp as is in the corner next to sofa. Hassock in front of sofa with a tray for drink, etc. Plant on the othe end of sofa to create a sense of quieter, secluded spot.

I like the 1st and the 5th pictures.

Sofa against BACK wall is best. Take out the tree!

No to a mirror over sofa. Get two standing lamps to flank the couch, a great rug, a piece of ART over couch........

Get a cocktail table that can be reached from all seating, ( lose the little table) and DON'T crowd a minimal space. The Lucite desk? better without it.

Think less as it is almost always m.o.re in result: )

I like the layout with the sofa across from the window and the chairs under the window best. I think you need a round side table between the chairs. And then either side tables on either side of the sofa if there's room or maybe a small cocktail/coffee table instead. I think the lucite table under the art piece is inoffensive but might be making the space feel crowded. Lamps on either side of the sofa would be nice.

When do you use this room and with how many people? It looks to me like an extra space that you are over designing to be a sitting area for more people than will actually end up using it. With all of that seating in a small room it looks like a group therapy space that nobody wants to go to.

I think the space would make much more sense as a cozy solo nook. I think the first pic you posted is fantastic minus the chairs. The sofa looks cozy, the ottoman looks nice under the clear table. The artwork and lighting looks soft and welcoming. I'd gladly spend alone time on the sofa reading or talking on the phone, or taking a nap. Use those lovely chairs elsewhere. In this little nook, less is so much more.

(I hear you about estate sale addictions. You've found some great stuff!)