Answer:it is an example of oxymoron
Explanation: oxymoron means when two terms having opposite meaning come together
Here unpopular celebrity is an oxymoron.
celebrity as the name suggests is a person who is well known and popular among people. oxymoron is often used in poetry to enhance the poetic language..it is a phrase that consists of two unrelated words. So here celebrity is attributed with the adjective unpopular which is very controversial.
Hope it helps ❤️