Both times it symbolizes something important to the plot; represents the breakup of the family. The first time the menagerie fell apart because of the fight that Tom and Amanda were having and the bad blood that was building because of it. The second was when Jim was driving Laura. The family was in pieces as a fight between Amanda and Tom had not been long behind the menagerie breaking and since Jim broke the figure foreshadowed that the fight was over Jim being Engage. This led to Tom leaving soon after. The breaking of the glass also symbolizes the breaking of Tom and Laura's dreams. The first interruption was foreshadowing of Tom's travel dream as it shows the bond he has with his sister. It was obvious that the relationship was too strong for Tom to walk away without regretting. The second was obviously that Laura would find out about Jim and be disappointed. Amanda's dreams are shattered in both cases as her dream is to make her children happy even though she tries to do so by living through