 The green light that shines at the end of the dock of Daisy's house across the Sound from Gatsby's house is frequently mentioned in the background of the plot.It has variously been interpreted as a symbol of Gatsby's longing for Daisy and, more broadly, of the American dream.In addition to exploring the trials and tribulations of achieving the American dream during the Jazz Age, "The Great Gatsby" explores societal gender expectations as a theme.