What is this cassette / hanger combination please?

[Squaredisk]

Here is a more recent version of the same. Lots of pics to show how it works.

IB17: Wild Mandaric 'Standard 21.5' concept runs the cassette outside the frame

Cassette outside the frame? 21.5mm carbon spindle? All new derailleur design? Mandaric's Standard 21.5 concept has it all, and may just be the future.

bikerumor.com

For some reason i think the bike in the OP actually might be a Motobecane.

@Frankenorange that is interesting. The owner has removed the sale images now - maybe we will never know!
I read about Bivalent hubs which were a vintage thru-axle design.

 

[sunympholepsy]

Interesting about the 8freight! (had a Google of it)
The tube decal makes you say Vitus 788?

Just a guess. It looks to me like a Vitus or TVT tubing decal… Not that’s that relevant. Just thought it might help narrow down the search slightly