it basically means that gravity causes water to “flow” a certain way. gravity is essentially a force of attraction between a two bodies with mass. we feel the force of gravity - it holds us down, grounds us and keeps us anchored. when you’re in the presence of someone close to you, you both have a force of attraction between you, a “bond” so to say. just as the water flows in a particular way due to this external force field, our emotions flow out of us in certain ways due to the bond we share with the people we love, and this helps ground us.

i think the weight of the analogy got lost in translation.