The 29-year-old singer likes the rebellious attitude in people, reported Contactmusic.
"Because she's owning it and it definitely comes from her. She's rebelling. I love her. If you wanna put your body on display like that, it's absolutely fine," Allen said.
"It's when somebody else tells you that you need to do that in order to sell your product that's offensive," she added.
Cyrus was criticised heavily for her controversial performance at last year's VMAs and her Bangerz tour.