The ending scene in the drama helps to bring out many of the central ideas that had been present throughout it.  One such idea is the construction of what is "normal."  Laura's disclosure that the broken unicorn is one that now looks less "freakish" than the other figurines is a part of this.  In her giving it to Jim, it is symbolic of how individuals view the desire to be accepted, to be normal.  This idea has been present throughout the play.  Amanda's demand that her Laura be "normal" in welcoming "gentlemen callers" is evidence of this, as well as Tom's outward "normal" appearance of a job as a shoe salesman.  This idea of what is normal and what is "freakish" is something that is brought out in the last scene.  

Another element brought out in the last scene that is present in the drama is the collision of emotional rawness between characters.  Throughout the drama, the rawness and discomfort between Tom and Amanda had been evident.  Both characters' emotional polarities had made coexistence difficult.  Yet, the ending is one in which this can no longer be denied.  Tom's departure and Amanda's sense of hurt and outrage can no longer be concealed.  Their rift, in particular Tom's displacement, is what begins the drama and comes full circle at its end.