Aha, here's the whys and wherefores of Fierrabras's giant furniture

Apparently --

Wisely, and entirely according to his usual stage practise, director Claus Guth has chosen not to stage Fierrabras as a naturalistic Moorish drama. However, despite the good intentions, eventually he does, for once, somewhat miss the mark here. The entire opera takes place in Schuberts studio. Or perhaps even in Schuberts brain. 
An actor plays Schubert, who also occasionally speaks, conducts, escorts the singers on and off stage etc..All in a miniature world, with oversized furniture and singers presenting small symbols (a crown, a wooden bird etc) to clarify their position in the play. Clearly, Claus Guth thus wants us to be part of the creative process, but for more than two hours it becomes more than tedious. 

In other words,  eurotrash   Regietheatre... RegietheatER? Not sure.

(About the spelling, quite sure of what I think about the practice.)