The central element of humour that lies in this excellent play is the farcical nature that is pointed towards by Chekhov in the subtitle that he gives this play. Of course, the majority of the humour stems from the way in which Mrs. Popov has declared herself to be "dead" even before she has actually died as an act of grief and love towards her dead husband. To demonstrate the depth of her love for her husband, she declares that she will forsake life until she herself joins him in her death. Note how she presents this declaration in scene 1:
When Nicholas died, my life lost all meaning, as you know. You may think I'm alive, but I'm not really. I swore to wear this mourning and shun society till my dying day, do you hear? Let his departed spirit see how I love him!
Thus the stage is set for Mrs. Popov, in spite of her self-confessed intention to remain in mourning and to never love again, to actually fall in love, with the most unlikely character, the "bear" of Smirnov, who, through his brash anger and rudeness, ends the play by kissing Mrs. Popov, obviously foreshadowing their marriage. Thus the central element of the farce of this play lies in the gap between words and actions, intentions and reality.