My brother and his wife had this in their house and it is beautiful...................
It seems that you can pick up rocks and misty water it daily that already have moss on them or you can add it to the rock and water it to grow. Julie, my brothers wife said that if you blend up yogurt and moss in the blender, that you can simply paint it onto the surface of what you want moss to stick to, and water it to grow, though I have yet to try this method. Apparently, the yogurt helps the moss to grow.
They got a misty squirt bottle, and keep it in a shaded place in their house where there is moisture and it is flourishing. I love the creeping jenny coming out of the top. That is an added bonus.
I started collecting my rocks yesterday to do this very thing on a much smaller scale. Excited!