It all adds up

 These were apparently taken in 1972 at a surrealist themed party thrown by the Rothschilds

 Rothschild <3 goat's heads

This was what the outside of their mansion, the 'Château de Ferrières'  looked like on the night of the party, they had red and orange spotlights projected onto the building, moving around to look as though it was on fire. A reference to hell, perhaps?

The invitations were sent out on card with a Magritte style sky, only they were printed reversed so they'd only be readable when looked at in a mirror.

 Rothschild party or set of Kubrick's Eyes Wide Shut??

 Audrey Hepburn, Magritte style birdcage

Dali is said to have designed the hat that Baron Alexis De Redé is wearing.

 Here Dali is, at a Rothschild party chatting to Italian princess, Maria Gabriella de Savoia.

If one watches Stanley Kubrick's movie Eyes Wide Shut, starring Tom Cruise and Nicole Kidman, you'll see a small glimpse into the secret social world that co-exists alongside a watered down mainstream. It just so happens that the main ritual/orgy scene in the movie was filmed at Nathaniel Rothschild's mansion in London.

This seems strange to say the least. I found these photo's here:

http://scalaregia.blogspot.co.uk/2010/01/air-de-la-folie.html
http://reallifeiselsewhere.blogspot.co.uk/2011/08/diner-des-tetes-surrealistes-1972.html - Thanks for posting them!