When Marshall asks who would take the unused room in the apartment if he were to move out, he uses Barney as humorous possibility. He says that Barney cooks in the nude. In "World's Greatest Couple", Lilly cooks for Barney, which makes Barney mad, as this is a change from his normal lifestyle, which does not involve having food cooked at his place.
When Barney is convincing Ted that Lily moving in will mean he's being edged out, the position of the coat on the bench back behind Robin shifts between cuts, going back and forth between hanging over the edge of the back and being laid sever inches from the edge. Then when Barney leaves to sit with his date, in one cut it is completely gone, only to reappear again.