The English term Complex Seeing is taken from Bertolt Brecht's writing on theatre and opera. First found in Brecht's notes to the "Threepenny Opera", a subsequently edited and updated version was published. This text can be found in English translation as "The Literarization of Theatre" from 1931, in Brecht on Theatre, where the key passage on complex seeing reads:
Bertolt Brecht often wrote about theater and opera.
The context mentions a work titled Brecht on Theatre, which would imply that he wrote frequently enough about theatre and opera to have enough material for a book. The system probably took offense to the term "often" since that opens the door to vagueness in interpretation compared to just saying "Bertolt Brecht wrote about theater and opera"