Actually, Transformation, referred to as "Hua", is simply an upgrade of Inner Strength, its power is still being emitted from the inside, but the key lies in the word "Hua" ("Transform")!
"Hua" conveys the idea of transformation.
The masters of Inner Strength possess tremendous power when exerting it, yet they are not always able to control it fully. However, Transformation Grandmasters have honed their Inner Strength to perfection, with every move carrying the force of Qian Jun and displaying infinite variations.
At the level of Transformation Grandmasters, there is often no need to stick rigidly to specific moves, and every palm strike or punch carries possible transformations.
Furthermore, Transformation Grandmasters have keen senses, able to perceive external objects and forces in relation to their bodies. It means that even if a Transformation Grandmaster is blind, they can still react to someone else's punch by leveraging this perceptual ability.