Festipedia:Popup documentation
The Notifications Popup is a gadget that provides a "pop-up" on the top right of any Festipedia page if you have any unread Notifications (as defined in your Notifications preferences). It was designed in response to concerns about the visibility of the new Notifications alert.
The pop-up will disappear from the page after a few seconds. It will continue to appear on each page you load until you read your notifications by clicking on the red badge next to your username.
Though the gadget is ON by default for all registered users, you can easily turn it off by going to your Gadgets preferences and deselecting Display a popup when you receive a notification under "Appearance", then saving.