After seeing the room, I have to say I like the first picture of the Seine better. I can't tell what colors are in the rug, but what about using a fabric wall hanging rather than a picture or a mirror? To tell the truth, my eyes glazed over from staring at this one when I saw it on ebay; at first glance, it might seem too primitive for your refined room, but properly hung, I think the contrast would be smashing. Here is a link that might be useful: Wonderful handworked wall hanging

Love Beverly’s second one ... that kind of antiqued glass is beautiful. And those sizes she’s showing really make a statement. Mirrors don’t just have to reflect something gorgeous on the other side of the room ... they’re art in their own right and are wonderful at reflecting light, adding dimension, and making a room feel bigger. Classic design. This thread made me think of this link I’ve had saved a while: https://curatedinterior.com/parisian-fireplaces-mantel-decor/

Take the decor items off the mantle. They are too small to be effective. Switch the square art near the window, with the mirror. The square art is squished in that space and will look, I think, great over the fireplace. The mirror near the window will reflect both the view outside, and reflect light into the room. Remove the long rectangular art to the left of the book shelf. Too many contrasting rectangles everywhere in this room, including the blinds. You need to break that up. I see 2 round pieces of wall art, one on the wall near the dining table, and one on the floor. Can we see them in better close up? It's possible that the round one would be even better than the square art, over the fireplace. Is the fireplace wood or?

Mantle measures 91 inches in width and there is only 34 inches from mantle to crown mounding. Need to know proper size mirror??? single or several smaller ones??