I can't remember wich post it went on in. But there was discussion about the smaller icons of water/food. Now many refered to this as a bug. Me personally, I thought the small icons would indicate your water need, before you start bleeding.
HOWEVER, what this really is, is a small UI for your dog. We all know dogs has been spoken about every now and often. So that's why it's there. That's why not every server got this UI. Is there dogs on every server that got this UI? I got no clue. But I know for a fact that there are servers with dogs.