I liked the idea that each finger represents one of the Five Elements/Phases/Functions (Wood, Fire, Earth, Metal and Water).
Couldn’t find Bruce’s reference to that in the Manual–maybe I got it from his DVD.
When the fingers are connected the energies are united.
The hooked hand can be used to split open your opponent (I’m not a martial artist, but it’s helpful to imagine this) or the beak can be used to peck critical points on the opponent. Of course, there are many other uses.
My favorite analogy comes from the Five Animal Sports where the bent wrist contains energy in the hand like a Deer’s hoof. Usually we want to keep all joints open. But there are exceptions to everything in taiji and qigong.