Documents should be properly titled as per Success Criterion 2.4.2 (Page Titled). This simple example should pass the empty title checks.
This is added as a separate example because the tests generate a notice to inform the tester that the page should be appropriately titled. At the very least, it should give a descriptive title of the page, and preferably some form of context like the site name or a breadcrumb list.
In this case, the title has been left as "Untitled". This is not likely to be a suitably descriptive title for a page. Another example of an inappropriate title may be the file name.