As James Knowlson says, Beckett's intention was that this was an ironic comment on what followed, although someone had added 'with naked people' in the rubbish, and Beckett was very far from happy. The sequence was withdrawn from the London production of Oh! Calcutta!.
Breath is generally seen as a blurring of the difference between theatre and other art forms.
*This is a pun on Clovis Trouille's 'Oh quel cul t'as' ('Oh, what an arse you've got').