Gina, Gina, Gina... I read your questions, I know you are asking me about the wall decor and the corner... but I can't help but to comment on the whole room. I just can't leave it unsaid.
Let me start by saying what nice items you have. Individually, you have really selected some of my favorite things. There is no sofa I like better than a Chesterfield. I have a very similar one in my own home. Your large mirror is awesome! Your coffee table is terrific.
But... His and hers sofas? That reminds me of his and hers Lazyboy recliners, but yours is straight out of a Restoration Hardware catalog. I like making things perfect, and if you aren't letting me change your furniture, it's like, here is some pasta, chocolate chips and applesauce, help me make spaghetti. Sure- as soon as we get rid of the chocolate chips and apple sauce. I don't mean to be harsh. The selections individually are all very lovely. ;-) but...
1. When you have two parallel sofas, you need more space, so you can have two chairs, or you can have no chairs at all, but the one chair doesn't work. Can you see that? Consider moving the chair to another room.
2. Three different leathers. That lack of textural variety in your upholstery is not good. It makes me a little sad, because it all looks so nice and new. Honestly, I would move one sofa to another room, and move the chair to a third room. They are all great- but don't belong together. Your e-mail makes it sound like you won't do that- but the beauty of this blog is that I am going to pretend that you did. (Don't you e-mail me and tell me you're not doing it.) Now, go get a matching sofa. I'd like a couple of "hers" sofas. ;-) (or his...) I never have two sofas, or even two chairs that are the same style with different upholstery.
Now your room looks something like this:
3. Let me tell you about your wall decor. It is all about relationships. When you do not have any furniture against the wall- your wall decor should have a relationship in size and scale to the wall itself. Having the corner of a diagonal sofa sort of touching the wall does not count. Look at the photo below. This is an excellent example of how to treat this wall correctly. You'd need a whole heck of a lot of wall decor to have the correct scale for a wall that size.
I took that picture from this post, where I go into it in more detail. However, you already have this beautiful zinc mirror. Can you use that in a collage? I think it is too dominant and too deep to mix well with other items. So- what can you do? I just discussed this recently, in this post.
You can change the game by adding a piece of furniture to the wall. Now your wall decor should have a relationship with the furniture that is beneath it. Add a chest or console table. Make sure the size of the furniture is a good scale for your mirror that you already have. I would still add more wall decor on the right side of the console table, perhaps a collection of art. Not just one piece like you currently have, more like five pieces of different sizes. You can do a search on my site for the word "relationships." There might be a thing or two about my husband, but mostly, this kind of relationship issue I have discussed many times.
4. The corner? Add some decor to the table, and a plant. Easy Peasy Lemon Sqeezy as my nine year old would say. A lamp, some pottery, that kind of thing. Check out the collection below from West Elm- You could repeat that exactly. If you are ever unsure about your ablility to accessorize, the styllists for magazines are pretty good at this kind of thing. Just copy it. Right down to the two rocks. -Add a lamp, and a large plant with an uplight in the corner and it would look great.
There you go- I hope I was more helpful than harsh, what good am I if I don't say how I feel? Right?