It was a really fun encore stage with Day6 members Young K and Wonpil, who were special MCs this time. One of them forgets to give away the trophy, Chaeyoung has to ask for it. Then Nayeon bullies them into staying for the encore. Twice tried to get them to dance to Signal, and I guess they didn't really know it because it just turned into a messy medley of past Twice dances.
sources: Twice Fantube, M2, Mnet Kpop