I just checked the Secrets of the BW book for you (pg 175) and it says
Stage 1: The Window - yawning and showing tired signs, get her to bed
Stage 2: The Zone - baby has a fixed focused stare, the 7-mile stare, eyes are open.
Stage 3: Letting Go - Baby resembles a person nodding off on a train, closes eyes, head drops forward, eyes suddenly open and head whips back. Repeats 3-5 times before entering dreamland.
Tracy says on pg 178 (in my book anyway) to put the LO in bed at the beginning of stage 3 to give her the chance to develop teh skills she needs to go to sleep on her own.
But this is for early days when you are first getting started with independent sleep, the final aim is to be putting them in awake.
HTH
Ali