[jvasel]

I don't know if this is the same for Orchids, I would assume so. But on most angiosperms (flowering and fruit bearing plants), plants come with an Axillary Bud located between the stem and the petiole of the leaf. The Axillary Bud is an region of growth, however normally a hormone called Auxin prevents it from growing so that the nutrients can to to growing the plant upward, rather than from the sides. If the Apical Meristem (growth area at the top of the stem) is removed, the Axilary Buds begin forming new parts of the plant such as leaves and flowers.

Perhaps what they did was harvested a leaf and provided the proper hormones to allow this area of cell growth (Axillary Bud) to be come active, and the used the method that jerry mentioned above before cell differentiation occurred to produce many cells. Once they stop rotating, the plant cells use gravity to determine which ones become root cells, leaf cells, etc.