The set, a palace garden surrounded by 3 high walls (which might have been the set of his 1980s 'Magic Flute' in Glasgow minus the books), with a palm tree in the middle, does not make sense. Why should a palace entrance, with a rather minor door, be set back between two walls? Or is it the tradesman's entrance? The costumes are pure 18th century - so it's as traditional as you can get. Klaus Maria Brandauer, an actor who plays Bassa Selim, rather shows up the non-native German-speaking singers with his natural speech. He has a rather high voice for 'authority' characters who in Mozart tend to have a low voice (eg Sarastro in the 'Magic Flute', or Don Pedro in 'Don Giovanni'). Alfred Muff as Osmin is rather restrained, and not the rather evil but also partly funny character that I would have expected (another parallel to the 'Magic Flute' 'singspiel' - Monostatos; both are made drunk, the first with alcohol, the second with music; perhaps showing, in a rather racist way, how 'simple [foreign] people can be easily manipulated).
On the other hand, this opera could easily be seen, and treated, as an East-West (euphemism alert!) opera, eg setting it the 21st century, for example in Afghanistan or Iran. That might have been interesting - but would any opera house have touched it, these days? Think only of Osmin's aria (freely translated) '[they will be] beheaded, then hung, then stuck on hot spears etc' (how can someone be beheaded and then hung??). And that might be dangerous, and start up a lot of trouble. Maybe that's what they were trying to achieve in this production - but it's dull! I'm off to bed!