Literature Reference: When the horse's head brushes the willow, it reins back momentarily; the leopard tail pierces the flowers, pausing the spear. Source from 'Early Spring with Liu Langzhong to Linghu, the Duke of Xuanwu'.
回: Winding and meandering.
辔: Reins and harness. The bit and bridle used to control and guide draft animals.
Meaning: Reining back the horse signifies the ability to advance or retreat with grace and composure.