Cant really tell the rest of the décor or it may not be in place yet but this looks like it will be the focal point in the room. Besides a TV niche of course. I would surround it with a tile or rock or glass or mosaic tile that matches the decor then surround that with the matching trim from the floor. Off to each side where the pictures are you could put battery operated sconces, or tea candles, that have a darker glass when not lite and a flame matching color glass when they are lit.

SlateFlex would look nice on than wall similar to http://sainteriordesignstoronto.com/treasured-moments.html

That is an great whole room décor. Love it. Great site to for lots of new ideas. Thanks for sharing.

It would need a heat shield/backer board of some kind to prevent it from reaching the interior walls. I have one in my lower level as well and the whole wall was done with it before I tiled it.