Having a picture showing the entire fireplace would help.

Well first of all, I have to comment on the pictures jalarse posted - those mantels! Those ships! All that amazing millwork! And the extent of the themes down to the whimsical oars! The work of some true artists there - I really enjoyed those pictures. This one was a toughie for me! I’m just going to ask and throw it out there - you can completely ignore me, but are you considering painting the brick? I only ask because I think the color of the brick is a bit hard to determine in pictures and the walls (and light at night) give it a strong yellow cast. With it going all the way to the ceiling it certainly makes itself known in the room. Not a bad thing by any means (I promise I don’t always want to paint brick), but I think paint would allow for art or the mirror to be the main focus of the mantel instead of the brick. Ok! Off my paint box... I think as you suggested, a mirror would look lovely. I think we all have a tendency to try to fill such a tall space but as long as the mirror is wide enough and the accessories large enough in scale, we can keep the decor close to the mantel while maintaining a full, finished, and proportional look. I mocked up a simple, symmetrical look - this mirror is from Ballard Designs “select-a-size” collection as your fireplace can definitely handle a large, wide mirror. A chunkier frame will keep it from disappearing into the sea of brick. The hurricanes are the London hurricanes from Crate & Barrel and they are affordable and come in multiple sizes. The largest and second largest sizes will look best. These accessories can be built upon based on the season and/or holiday so you can hang your wreath from a grosgrain ribbon on the mirror and fill the hurricanes with whatever seasonal accoutrement strike you. And I threw in some linen roman shades from pottery barn to give the windows a more finished look. Hopefully that helps inspire you to find the items that best speak to you for the space. Oh! And those cutie pies on the mantel would look great front and center on a table a bit lower - like side or end table. Have fun decorating!

I would leave the tv where it is. To decorate the rest of the mantle, be careful with scale. You currently have a bunch of small things so it looks cluttered. Instead of the 2 small framed pictures, replace with 2 much larger pieces, almost the same size as your tv, and move them towards the corner. They will balance out the tv on the other end. Then add a few smaller things, but not a lot. I think I counted 15 things on your mantle and not counting your tv. That's WAY too much stuff. You should have the 2 large framed pictures, the tv and 3 smaller things. Then stop.

I agree that less on the mantel is best, more focus on the sign. I am also not a big fan of prefab fireplaces with louvers. Even though it is a blatant distraction, most people overlook this and don't realize it can be hidden like this: Shown Above: 1P30M Labyrinth Fireplace Screen with MAN-9 Gallery Andirons in Statuary Bronze. Here's a picture of the Labyrinth screen in Polished Nickel. This entire piece is made from solid brass and then finished in many different options. The Labyrinth pattern hides what is behind it very well. Shown Above: Custom Fireplace Screen with double woven mesh in Dark Bronze. If you paint the existing glass door frames black they will disappear behind the double woven mesh. Provided by: Free Fireplace Design Service at Hansen Wholesale