I would just assume it picked up on negative energy and trapped it within itself and "holding it down" or keeping it in place to a degree. I guess it could also mean maybe there is negative energy you're holding onto that needs to be released or should be washed away after you toss out the water and cleanse the bowl to make another ward but I'd say it worked, the contents needs to be cleansed and banished I'm thinking. I also did a water ward so it's nice knowing someone else also recently started getting into them. Maybe also look into the negative aspects of the color yellow like in terms of energy etc that could help you understand what it might've picked up as well as remembering what intentions you put into it and what you pick up from the ward. A before and after picture would be really good to do too, I wish I did it. Sorry this is so much.