Jessica was trying to stop Sooyoung from locking the Cyrano HQ so their future client can enter the HQ. Sooyoung didn't want to accept any client because it was her "unlucky day" and Jessica wanted to help the client. When they were "fighting" beside a couch, Sooyoung slipped and she fell on top of Jessica while Jessica fell on top of the couch. And that moment became one of their unforgettable memories.