The venue is reportedly the Hotel de Ville, which has a fascinating history of its own. And is, clearly, totally hideous and what a miserable eyesore that ceiling is, how did any of those people bear it, etc.
The twins. What I can't tell is if they're played by ACTUAL twins.
Apparently the unicorn was made by the people behind War Horse.
Let's Get Mega-Zany with Thom Browne
It was a "Little Mermaid" theme. Well, except for the unicorn.