This is a halter neck top from Balenciaga by Nicolas Ghesquière.
Iro
Etro
Blumarine
Zimmermann
La Double J
Alemais
L'Idee
Missoni
By Malene Birger
Stefan Cooke
Farm Rio
Zadig & Voltaire
Pucci
Nissa
Giorgio Armani
Anonyme
Bless
Diesel
Moschino