What is Blanche's conflict between the forces of illusion versus reality?

In Scene
10, when Blanche is being pursued by Stanley, the stage directions indicate that "Lurid
reflections appear on the wall around Blanche." These reflections "move sinuously as
flames along the wall spaces," and the wall becomes "transparent." Through the
wall we can see a "prostitute" struggling with a "drunkard." A little later,
as Stanley bursts through the bathroom door, and as Blanche backs away, terrified and desperate,
the sound of a "blue piano" can be heard, and the sound "turns into the roar of
an approaching locomotive."

The reflections and the transparent walls
and the music are all projections of Blanche's emotional and psychological reality at this
moment in the play. Though they are visible and audible to the audience too, they are not
representative of objective reality. In this sense, they are illusions. This method, whereby the
appearance of the stage is manipulated to reflect a character's inner reality, is commonly known
as "plastic theatre."

At this moment in the play, Stanley corners
Blanche, like an animal cornering its prey. It is implied that, after the scene, and offstage,
Stanley rapes Blanche. When the reflections appear on the wall, looking like flames, they
constitute an illusion which conflicts with reality in that they are not objectively or
literally real. However, the illusion of the flames actually mirrors reality more than it
conflicts with it. The flames mirror Blanche's inner reality in the sense that they represent
the danger that she feels is closing in on her. Blanche's inner reality here is arguably far
more pressing, and far more significant, than the literal, objective reality of the
play.

When the walls become transparent and we see the drunkard wrestling
with the prostitute, this too is an illusion, but this too mirrors Blanche's reality as much or
more than it conflicts with the objective reality of the scene. The drunkard here represents
Stanley, and the prostitute represents Blanche. Indeed, throughout the play Blanche sees
herself, through the eyes of others, as a prostitute, or at least as a woman who has been
promiscuous. The illusion of the prostitute and the drunkard thus represents the reality of her
own perception of herself.