This is a great combination balcony with stone and grass providing different layers of look.
The stone can be hand placed or bought in squares and laid down while the grass is probably the popular faux grass which is quite incredible in its realism.
Underneath all of this you need some sort of water drainage system, so that that it not only drains but also for the heat/cold changes which can occur between the layers. The wood in this case looks like a hardwood, so there will be less expansion there but oddly enough the grass backing, which is usually black, can expand so a small space between it and the stone is required.
A nice job all round and a good use of the three different materials to create a great looking balcony. Here's some other looks using grass in a similar situation.