A Nailed-Up Coffin

I noticed an example of symbolism in scene 4 of The Glass Menagerie of Tennessee Williams.  In this portion of the scene, Tom talks about seeing a magic show at the movie theater.  The last trick he describes involves the magician being nailed into a coffin and then escaping.  On page 1249 Tom points out the symbolism, saying: "You know it don't take much intelligence to get yourself into a nailed-up coffin, Laura.  But who in hell ever got himself out of one without removing one nail?"  This shows Tom's frustration toward his current situation.  He wants to escape from his current life and live a life of freedom and adventure.   However, he is stuck working his current job because his father left and he must provide for his mother and sister.  He is stuck inside his own coffin without any method of escape.  On another level, the coffin is a metaphor for his father.  In the stage directions, it says that the picture of Tom's father lights up as if to answer the question.  His father managed to escape his own imprisonment by fleeing from the family completely.  When examined under that light, Tom's symbol can be seen as foreshadowing of his own departure.