Potted plants are grown in clear plastic pots in live red sphagnum moss (Sphagnum capiliifolia).
1. Live sphagnum only takes as much water as it needs to survive, so it is a loose, free-draining medium that doesn't retain water. Whereas dried sphagnum can become waterlogged and cause the roots of the orchid to rot.
2. Live sphagnum doesn’t break down over time like dried sphagnum, so the plants don’t have to be repotted as often.
2. It's also plausible that as it respires, it might create airflow around the roots and keep the roots cooler. It might also provide moisture to the roots through respiration.