After the pulling elbow, both hands come to the hip in a classic "teacup" chamber position. It's called a teacup because the near hand is horizontal (like a saucer) and the far hand - the one that is reacing across the body is vertical, like a cup on top of a saucer.
"This is a chamber - pulling back to get ready to do the next movement strongly." Nope. The moves that we call "chambers" (I dont know where that term came from) aren't wasted getting-ready moves. All movements in the kata have to be potentially useful for improving your condition and/or injuring the opponent. So what is teh teacup useful for?
- Your opponent grabs either of your wrists with either of his hands, you countergrab with your free hand and release your held hand as you snatch both hands to your hip, pulling opponent offbalance.
- Alternately, you could directly grab one of his sleeves with both of your hands in the same place and snatch him offbalance with both hands.
- Additionally, if you combine this teacup pull with the type of footwork seen in naihanchi - a cross-step or a sideward slide into a horse-riding stance, then you have just executed a classic Japanese pass - moving from a position between opponent's arms to a position behind and outside - in the opponent's dead angle (shikaku)
This third application illustrates an idea that I consider to be fundamental to understanding naihanchi - the moves don't have to happen in the order they are done in the kata (they can be but they dont have to be). They can be combined in nearly any order in limitless combinations, and usually result in useful offensive motions. In the third example above, the teacup is combined with the cross-step, but in the basic, mnemonic form of the kata, the teacup is done in a stationary horse-riding stance.