Some expensive bike that had been sold to some schmuck with more money than sense.
Sometimes people have a particularly bad back and if they can afford it they tend to buy full sus bikes and set them up with very high bars and cushioned saddles, exactly like that one, just for pottering around on. You could argue it might be wise to fit a conventional stem to sell it, but they just got a load of free advertising by keeping the extender on there, so…
The tandem’s just a tandem built in the style of a Halfords Special. It’s not pretty as a result, but if you want a tandem and you don’t have a wad of cash it’s an absolute bargain.