what ever you hang over the FP should be about the size of the firebox. what would the mirror reflect? it seems too high for a mirror

I have a chandelier so you maybe right about the reflection. I hadn’t thought of that.

The current art is too tall. Judging from the nearby doorway, it looks like your fireplace is very high, so a wide short piece of art is in order.

There’s no need to decorate walls way up above your head.

The mantel is 70 inches high. The bookcase to the left is also tall plus the opposite wall is also a 2 story height. So I was thinking either a round or arched mirror or in the past I had a 48x48 piece of art. I have used large pieces of art in living room & visible foyer area so I won’t be able to do anything on too small of a scale.

That art is 43x43

Imo what you have now is perfect. It does not appear to be too tall or too narrow. I think it is perfectly placed. I would add interest in the area with interesting art. If you want to break up the square pieces, you could select art that has movement in composition.

I had brought that home just to try it out but the blue is more turquoise looking in person and my chairs have a faded linen look. I love the bottom have of the art. If I have to add pieces to fill in the gaps, that side of the room is going to look heavy.

I was looking at this it’s a 48x48. I have 2 chairs in this fabric & off white sofa & love seat.

I also looked at this which seems to blend better? Again it’s a 48x48. The only downside side is that things may look boxy. The chandelier, clock, tables are round. I’m assuming that helps?
I’m liking this one best?