How does Peter Brook use imagery in The Empty Space?

Imagery:

"[a] beautiful place may never bring about explosion of life, while a haphazard hall may be a tremendous meeting place; this is the mystery of the theatre, but in the understanding of this mystery lies the only possibility of ordering it into a science." p. 73.

"When emotion and argument are harnessed to a wish from the audience to see more clearly into itself - then something in the mind burns ... it is the play's central image that remains, its silhouette, and if the elements are highly blended this silhouette will be its meaning, this shape will be the essence of what it has to say." p. 152.