A Meg Biddle cartoon in the June 2015 Funny Times:
Yes-no questions with the tag or what? are regularly used to emphatically assert the truth of the questioned proposition. So
Is this a great country, or what?
has the effect of proclaiming that this is indeed a great country. But the question has at least one other reading, merely asking for an alternative answer to Is this a great country?, and that’s the reading Biddle is playing with in the cartoon.