It's all just an act, and it's pretty obvious. In the video, one of the Heroes staff slightly pushed Narsha toward the left to block Jiyeon and pushing her further left so then left the room for Eunjung to say 'hi' to IU. While merely hugging with IU, Eunjung kept looking back toward Jiyeon to see Jiyeon's reaction. Poor Jiyeon! T-ara just wanted to pull a prank on her, and she looked quite mad there for seconds. The strong maknae finally got bullied by her unnies I laughed so much when WAYBLT and Lies were playing. Pretty spot on!