What is irony in the play ? a appearance and reality ?

Yes, the driving theme behind this play is appearance and reality. Even though we today believe that one's behavior – in terms of “low” versus “high” class behavior – does not necessarily indicate who someone is, many characters in the play are often blinded to a character's behavior because of an assumption. For instance, Marlow and Hastings treat Hardcastle cruelly because they think him the landlord of an inn, and are confused by his behavior, which seems forward. The same behavior would have seemed appropriately high-class if they hadn't been fooled by Tony. Throughout the play, characters (especially Marlow) assume they understand someone's behavior when what truly guides them is their assumption of the other character's class.

No