-Billie says the water is a metaphor for abuse. "I'm in this house on the phone...and there's water dripping into the room from the ceiling and I'm not noticing it because you don't know when you're getting abused."
-Opening the door and having the water rush in "is a metaphor for not noticing how bad the situation is until it floods."
-Also discusses how much she has learned since she first started directing her music videos. The video is sponsored by Adobe.
Sources: 1, 2, 3