Bonjour Denisa,

Nowadays, I would say that both are accepted (the French adjective "iconique" has taken on the meaning of the English adjective "iconic" in "recent" years). Although, in this instance, the best option is still definitely "emblématique". 

See here: https://dictionnaire.orthodidacte.com/article/definition-iconique

I hope this is helpful.

Bonne journée !