That is a whole lotta white. Your very nice mantel looks just dwarfed by the height of the walls. Could you beef things up with bookcases on either side, to add a bit of height in the furniture, and use some color to tone down all the starkness?

Maria, it would be helpful to show us more of this space. I think a mirror there is wrong for a few reasons. One it is a tad wide. Whatever you put there should be oval or portrait, not landscape in shape. What is the mirror reflecting? A painting would be much better there. To the right you could put a nice bookcase or dresser with drawers and a lamp. Need to see more of room to really help.

The fireplace and surround is too small for the size of the room. I am suggesting using thin stone veneer from floor to ceiling. Widen the fireplace so the stone goes up to the column on the left and use the same distance on the right.The stone installed will go from floor to ceiling. Depending on the stone style you select you can keep the attractive surround or make the entire area in stone. You will want to use larger pieces of stone to help fill the space and draw your eye upward.

I personally think there is too much white on the fireplace wall and a new softer color might be more appropriate. I would love to hear from some of the designers.

The pictures below are of stone fireplaces that we completed with our stone veneer that we made and installed.

Keep you wall decor down at eye level. No need to try to decorate upper walls. But I would do something over the mantel to the ceiling. This pix is a good example of my suggestions.

Your very contemporary all-white space is way cool, but can look cold without the addition of some color. Find an art piece you love for over the fireplace, and use it as inspiration for the colors you add throughout the room. Keeping the walls all white makes sense in such a contemporary space. Your traditional mantel in cream, however, seems undersized, dingy and the wrong style for such a dramatic space, and replacing it with something larger is not a major expense if you do it right. Someone handy with tools can easily replace it with a squared-off box that is both wider and higher than your current mantel. Flanking it with both storage and display space would also help beef it up, and could incorporate the TV for a sleeker look.