That was your status bar in your browser. Status bar usually displays your active connection and what it's trying to connect to at the time.
If you are using Firefox or IE you can turn off the status bar in the VIEW menu. If you're using Chrome it auto-displays the status bar when it's actively reading. If this is the first time this has happened it's likely the status bar got left on the screen. That might be an issue with Chrome. Let us know if you keep seeing it on a regular basis though.