Porcelain figurines break at their thinnest points first, usually an outstretched arm, a delicate finger, or a feather detail, long before the main body ever cracks. Double-boxing with zero empty space protects those fragile extremities specifically.
Pro tip: Save the original box if the figurine came with one designed for its shape; manufacturer packaging is often better fitted than anything you can improvise.
Watch out: Thin protruding details like fingers, feathers, or flower petals break far more easily than the main body and need individual wrapping before the whole piece is wrapped.