When you look at another practitioner's tai chi, it's tempting, especially in the beginning, to only look at externals. Does the practitioner do the same movements you've been taught? Is she performing the movements in a way that you've been told is good? Is his hand in the right spot? Is his timing exactly like you've been told to it should be? What's that funny stuff he's doing there? Never seen that before...must be wrong!
It's far more profitable to watch a master tai chi or qigong practitioner in order to pick up what you can about style. You're not looking for the moves you know. You're looking for the how.
In this 1997 video, Liping Zhu, acupuncturist and incredible qigong artist at the Qi Dragon Healing Center in San Francisco, performs swimming dragon qigong. When you watch it, look for the power and amazing smoothness of her movements. Watch how each movement comes from the feet and is channeled through her body and out through the hands. There's no extraneous movement, and nothing flowery here. This is direct, focused, and soft movement at its best.