Because Jimin in that costume was too cute and chibi costume Jimin is just AAAHHH and Jungkook dressed as a bunny just proves he knows exactly what his fans want XD <--- Ohmy God I just realized that KookieBunny is eating JiminSprout!!!
Imagine walking into a coffeehouse then ordering "rabbit tea". When the waitress in a french maid's dress serves you the cup along with some bread, a noticeable chibi Jungkook would be napping in the cup. WHAT WOULD YOU DO?