Comparing the two fragrances…

Amzan

La Lettre
Kira
Siena
Shared character
Both Kira and Siena feature a shared profile of fruity, sweet, and powdery accords. They both utilize a common base and heart of heliotrope, sandalwood, vanilla, musk, patchouli, peach, lily of the valley, raspberry, pear, sand, cassis, and passionfruit. Both fragrances are characterized by woody, green, fruity, fresh, sweet, and powdery qualities.
How they differ
There are no differences in the notes or accords provided between Kira and Siena.
Who each suits
Because Kira and Siena share identical notes and accords, they suit the same preferences for those specific olfactory profiles.