Why does Iris have a crown.I young kid who was a gym leader is now a campion not E4?!
The Elite Four (Japanese: 四天王 Four Heavenly Kings) are four Pokémon Trainers who are regarded as the toughest in their regional Pokémon League, short of the Pokémon League Champion. Those who challenge the Elite Four must have won all eight Badges from that region and face all four and the current Champion consecutively without losing to any of them.
It's to show the metaphorical meaning of E4...that's why she has a crown.