In this poem (early 1950s) Bertolt Brecht expresses that the technical and functional happenings in the transformation of the staging are to be given to the view of the audience, if they lean back on their seats.
The choice belongs to the viewer in their dynamic action of viewing.
The peace dove by “brother” Pablo Picasso is to be painted onto the curtain (or in the case of the photo below embroidered). This action treats the work of this artist as an open-source visual devise, rather than as the original creation of a genius-art-god.
Art here is a collectively shared method, transparent in its performance and shared between people as members of the same uniting family.
Togetherness rather than exclusivity.