Final answer:
The voice that Laia hears in her head providing advice is likely a metaphor for her internal thoughts or influences such as past lessons or a loved one.
Step-by-step explanation:
The voice that Laia keeps hearing in her head giving her advice is likely metaphorical and represents either her own inner thoughts and conscience or the symbolic voice of another influence such as a loved one, past lessons, or even the collective voice of her environment.
The excerpt you've provided seems to deal with an internal struggle or a yearning for peace and rest, as referenced by the water crying. This could relate to a larger theme within the work that deals with personal or emotional turmoil.
Hence, the voice Laia hears in her mind, offering guidance, is likely symbolic of her internal thoughts or influences, such as lessons from the past or the wisdom of a loved one.