Tiling a fireplace?

[MLeffe]

I found a picture of a tiled open fireplace and want to do something similar with ours. I'm adding the picture I found and ours.
What we want is 2.5x2.5 mosaic instead.
The question is, is it even possible and what do we need to consider?

 

[Fridbritt]

I found a picture of a tiled open fireplace and want to do something similar to ours. I'm adding the picture I found and ours.
What we want is 2.5x2.5 mosaic instead.
The question is, is it even possible and what do we need to consider?

How did it turn out?