Her hooves look like actual horse hooves. I usually don't like it when artists take that approach but this just works. I thought the Iris meant "Happiness of the Believer," and was sort of an ignorance is bliss thing, but serves me right for trusting an anime. Awesome picture!
There's actually many meanings for flowers, it just depends where you look and what they're for. These meanings are more for giving them as a gift, I believe. I just chose the definitions that fit my purpose the best