Painted plywood mantle and surround

I built this fireplace mantle and surround for my parents house last Christmas to replace the squat white brick fireplace that they have hated since they moved into their house. It was an interesting project because I built it at home then traveled ~350 miles to install it, fortunately everything fit. It was built out of plywood, painted, then tiled. I had never tiled anything before and it left me a little frustrated, chiefly because I had to tile completely around the opening, which resulted in needing to tile on my back. If I were to do it again I would have used thicker plywood, just to limit the fuss from trying to glue the miters together while the ply flexed, but because it is likely to have a range of temperatures and humidities I think plywood was the right approach. All comments are appreciated.

If I can find other photos, without holiday decorations, I will post them.