Cupcake

Lemon and coconut, made specifically for the Cupcakes + Cookies Contest!
Also the first time I tried to do buttercream frosting properly, with a piping bag and all. It's clear that I need more practice with it. And more buttercream. It can't be helped, can it? I have to make more cupcakes.

Critique points:
Is the saturation and contast ok? It looks a bit over-saturated on the thumbnail, but sort-of ok full size... I only have a laptop to edit it on, and contrast and saturation on laptop screens depend on the angle I'm looking from.
Any buttercream frosting tips?
What about the composition? Does this cropping feel cramped? Too close? Should there be more plants?

Thanks for looking!