Final answer:
The simile comparing the lap-lapping of waves to liquid slowly emptying suggests Annie's departure from home is gradual and peaceful.
Step-by-step explanation:
In the context of the simile comparing the lap-lapping of waves to the sound of liquid slowly emptying out from a vessel, it suggests that leaving home for Annie has been a gradual and peaceful experience.
The use of this simile implies that there is a natural, almost inevitable progression in her departure, much like the steady and predictable emptying of a liquid. It conveys a sense of calmness and resignation rather than haste or chaos.