The Window
When Podkoliosin dives out of the window at the end of the play to avoid his impending marriage, the window represents more than just the physical. In jumping through, he is abandoning his only chance at marrying Agafya; the dramatic and humiliating way he leaves sees to that. By jumping out of Agafya's house, Podkoliosin is essentially completely jumping out of her life.
Agafya Tikhonovna
Agafya herself is something of a symbol. As the marriage prospect of Podkoliosin, she comes to represent all of Podkoliosin's marriage prospects. Even with Kochkariov's propulsive encouragement, Podkoliosin still finds a way to escape the confines of a life intended for marriage by jumping out a window. Since he fails in such a spectacular way to marry a girl he actually likes, encouraged by his best friend, he essentially proves his unsuitability for marriage in general.
Podkoliosin's Hat
Kochkariov takes Podkoliosin's hat and puts it in another room as insurance to prevent him from leaving in the middle of his visit and marriage to Agafya. Despite this precaution, however, Podkoliosin still finds a way to escape, even forsaking his hat in the effort. His hat therefore comes to represent Kochkariov's efforts to make him into a husband: it was a valiant effort, but in the end Podkoliosin will simply abandon it and flee back home to the safety of isolation.
French Fluency
In the eyes of Anuchkin, French fluency is the only qualification that makes a girl fit for proper society. In his eyes, it is a symbol of female gentility and dignity. In reality, however, Anuchkin himself speaks no French, and neither does Agafya, leading to a falling out of interests and disillusionment on the part of both.
Yaichnitsa's Girth
Yaichnitsa, one of Agafya's suitors, is described as quite a large man. His size is notable because it also represents both his personality and his temper. He is a dominating man in both respects; like his physical presence, it is impossible not to notice his presence in conversations, as he speaks with concision and impatience. Almost as soon as Agafya sits down with all the suitors, he pressures her to make a decision between them. He also has a quick temper, which along with his size causes Agafya to believe that he would beat her as soon as they were married. Yaichnitsa is simply a large man in all senses of the word.