I love your mantel and fireplace surround. But I agree with you that the mirror needs to go. Once you have done that I think you will find it a lot easier to do something with it. I wonder if you can take the mirror to a glass shop and have them cut it to a different size and frame it. Or buy a large frame that you like and get the glass shop to cut the mirror to fit the frame. That could then stay on the wall or lean against the mantel? Just a suggestion.

Attempting to take down the mirror may or may not result in broken glass, so consider that you may not be able to re-use it. It can be framed out with moldings in situ, if you want to keep it. Otherwise, a large piece of artwork would be nice.

When there is a mirror on a wall you always want a good reflection. I think your reflection makes it extremely interesting. The stairway and upper floor area. I think all we need to do is add some accessories to it. It is a custom mirror made especially for that specific area. You can tell by the shape & the fact that it is beveled.

We need some rather tall items to add to the mantle, however we need to be careful not to add too many. The candlestick idea is a standard choice , however there needs to be three in a group & they need to be much taller & with candles in them. I think you need to shop on 'Houzz' for 'mirror above fireplace' to get some inspiration. Try that 1st. then get back to us. Please do not try to remove it.

I think it's a fun backdrop for something large, bold, and lightweight. Here's the first thing that comes to mind, but you'll find something that speaks to you and sort of accomplishes the same grounding effect.

http://www.ebay.com/itm/Artificial-Walls-Boxwood-mat-52unit-12-x-12-x-1-5-Crafting-Topiary-Faux-Grass-/301530126785?pt=LH_DefaultDomain_0amp;hash=item46349899c1

http://www.thecottagemarket.com/2013/04/exquisite-emerald-green-exploration-of.html