Williams called the streetcar the 'ideal metaphor for the human condition'
The Streetcar is a real streetcar in New Orleans but also symbolises the power of desire as the driving force behind character's actions.
"They told me to take a streetcar named Desire, and transfer to one called cemeteries and ride six blocks and get off at Elysian fields" - literal and allegorical journey for Blanche.
Blanche associates the Varsouviana Polka with her husbands suicide, they were dancing the polka before he shot himself. Polka as a motif throughout the play when Blanche is disturbed about the past.
"The rapid, feverish polka tune [....] the music is in her mind, she is drinking to escape it"
Blanche takes frequent baths to "soothe her nerves" an attempt to cleanse herself and forget reality.
Through bathing, Blanche seeks rejuvenation - making herself look younger. This is a temporary respite, she never escapes her past "A hot bath and a long, cold drink always give me a new outlook on life"
The Paper Lantern over the light bulb represents Blanche's attempt to mask her sordid past and present appearance. Diffuses stark light but only a temporary solution - represents fragility.
"Put a paper lantern over the light [...]you've got to be soft and attractive"
Creates an illusion, soft glow from light - Blanche uses to get help from others.
"I can't stand a naked light bulb, any more than I can a rude remark or vulgar action"
Parallel between discomfort in light and sensitivity to Stanley's brutishness, shows her fragility, visually exposed link to be being emotionally exposed.
Whilst Stanley tells Stella about Blanche's sordid history, Blanche sings the song "Paper Moon' about a paper world that becomes a reality through love - ironic.