I assume she's trying to get Arnav to admit he wasn't acting and that it was really him as Arnav speaking not Ranjha.
Also, she's probably angry at the fact that Arnav always leaves everything in the middle and unfinished, like his dialogue to her. She is just a girl who wants to be loved and wanted him to face her and finish what he said, because she does have a tiny ray of hope that maybe, just maybe, the man she was blackmailed into marrying may actually love her.