The lack of electricity is an indication of Tom's irresponsibilty in not paying the bill. However, the darkness and candlelight afford Tennessee Williams better opportunity for the expressionism of his play, "The Glass Menagerie," thus furthering the theme of illusion. In such dim light, Laura can overcome her shyness surrounded by shadows. The expressionistic stage direction states,
Jim lights a cigarette and leans indolently back on his elbos smiling at LAURA with a warmth and charm which lights her inwardly with altar candles.
The "altar candles" represent the unearthly qualities of Laura and of her lack of connection to the real world. Truly, she is like her little glass animals who merely reflect the light. At the close of Tom final speech, Laura is seen blowing out these candles, thus ending the play. Tom says,
'For nowadays the world is lit by lightning! Blow out your candles, Laura--and so goodbye...'
The lights going out serves two purposes in the play. First, it establishes the need to light the candles. The candlelight creates a soft and even romantic atmosphere for Laura and Jim's time together. The candles, still burning, then light the stage for Tom's final speech at the end of the play. While Tom as narrator speaks, explaining what his life had become after leaving St. Louis, Laura and Amanda are seen in pantomime in the St. Louis apartment immediately after Tom had left, still in candlelight. The play ends when Laura blows out the final candle. Also, the lights going out contribute to the development of Tom's character when we find out that he had not paid the electric bill, but instead had used to money to pay his dues in the Merchant Marine. Tom had made definite plans to leave prior to Jim's coming to dinner, without telling his mother and sister.