Oh. This is their vision quest optional ad thing. Not that its great but these exist on desktop already, and can be completely disabled in settings. This post just now reminded me that they made that, I turned it off and completely forgot.
They also say that the option to disable it will exist on mobile too. Its shitty that there are ads at all but this is about the least offensive option I've ever seen. Can't promise it won't creep out and get worse later but yeah.
https://dgtlinfra.com/data-center-water-usage/
I found that article really informative, TLDR: a lot of water is recycled and recirculated yes but not all. Also they sometimes evaporate water for cooling, and eventually the water does need replaced. I think the concerns were mostly scale and water increasing in conductivity over time.