[CommerceComet]

In residential construction, you'd immediately think that some plumber didn't pay attention to the blueprints which called for a toilet and a bidet. And you'd also think that the plumber was a complete moron for not checking - who puts two toilets side-by-side?

I doubt that is the case here and I have no explanation for what happened here. However, I am certain that a moron is involved.

[Buckeye McFrog]

alternate theory....the plumber grew up in some Soviet-era apartment block where open stall communal bathrooms were nothing unusual.

[Freelance Warrior]

And you'd also think that the plumber was a complete moron for not checking - who puts two toilets side-by-side?

Simple: this is a spare loo: if the main one is broken, the other may be used without delay ;)