When executing filters manually quickFilters shows sliding alerts , but these do not work anymore apparently the interface nsIAlertsService.showAlertNotification has been deprecated and removed. see Bug 1236688
You can disable with the option on the quickFilters Pro settings page with [x] "Show a notification when running filter manually."
there are also other notifications that are triggered by function such as filter import, creating filters using a custom template etc.
It is also used to read out the license validation results for screen readers.