It made no sense, she knew, arranging flowers before the water was in - but there it was; she couldn't resist moving them around, and not everything people did could be in a correct, logical order, especially when they were alone.
The quote reflects the idea that sometimes human actions defy logic or order, particularly in solitary moments. The character feels compelled to arrange flowers even before the necessary conditions, like adding water, are met. This suggests an innate desire for beauty and organization, despite the lack of practicality.
Moreover, it emphasizes that people often find solace or expression in small, seemingly illogical tasks when they are alone. This act of arranging flowers symbolizes a need for creativity and personal satisfaction, illustrating that not everything in life must follow a structured path.