Fiat’s world car, based heavily about the 178 platform manifested in Europe since the old Brava/Bravo.
This isn’t a car to create the world burning, simply one to supply affordable transport towards the masses outside the western world.
Fiat’s rationale would be that the 178 model family is versatile, and ‘able to exploit all sales opportunities’. In short a differentiated response from the single project, that reflects the requirements and characteristics of every market.
It is hard to spot the difference between this and also the Albea. But in a part of the world brought up on Ladas and Polonezes, Siena seems to be awash with leading edge cool.