Based on the search results, "What Jhumka?" appears to be the title of a song from the Bollywood movie "Rocky Aur Rani Kii Prem Kahaani". It is a dance number sung by Arijit Singh and Jonita Gandhi, with music by Madan Mohan and Pritam, and lyrics by Amitabh Bhattacharya and Raja Mehdi Ali Khan. The song has become popular and has been the subject of various choreography videos on YouTube.