What's going on in the rest of the room. Can't provide you solution without seeing what you have and what you might need. Where is your TV?

Let me grab a few more photos. There are two chairs (you can see the edge of one of them in the photo), a couch opposite the fire place and a desk opposite the chairs. No TV.

Wall mounted etagere

Find a large picture, shelf, frame, art piece you love and voila! I wouldn't do a lot more small pictures if you're going to keep the pictures on the mantel, that's a lot happening on one wall. Maybe a plant also if you can keep them alive and are into that.

A bench with open legs (for the vent) and put the picture that you have over the fireplace on the wall above it. For the fireplace mantel, I can see a clock, some tallish candlesticks, some figurines.....just three items or five (uneven number).

If you are replacing tile/stone around fireplace soon, I would also rethink the fireplace surround and mantel. You could do a stacked stone all the way to crown molding and put nice rough honed mantel, lower than existing and perhaps hang picture offset to left with simple tall statues on right. Something like that. Then you can assess what you might want on the left of fireplace.

Here are some ideas:

You can see that just redoing tile will most probably involve redoing the surround. The one above, (black with stone) might fit your surroundings really well. Kind of "mission" style but with a bit of flair!

Your idea book on bonus room looks like your style is sort of Transitional. I would put a small buffet on wall next to F/P. Here is one I thought could be a good style for you. I would also redo the mantel arrangement to continue with a more artistic look.

As promised, this is the rest of the room.

http://m.ebay.com/sch/i.html?sid=profparts&_pgn=1&isRefine=true

Some wall art

Curious, but try putting the desk and chair there and moving one of the single chairs to the other side. Could then put art above the desk and a mirror above the mantle. I think two art pieces next to each other would fight.

otherwise an open bookshelf, like the leaning kinds could work, or a couple of floating shelves. Then put some nice things on them, without overcrowding.

I'm fine with print over fireplace, maybe take all those photos and gasp! I know some don't like them make a gallery wall. then you could add a candleholder or other smaller objects under print

I would change the art above the fireplace to something more rectangular. I think a ladder with luxurious textiles, or faux fur, or throws would be lovely and add texture and color too. :)

Group your framed photos instead of lining them up in formation.