the 'butt charm' [ xD ] is called a cutie mark. It can represent a talent, for example, rainbow dash, a pony in MLP [ you knew that xD ] 's cutiemark is a rainbow and a cloud. [ just look it up :U ] it basically represents that she can fly super fast and can do something called a 'sonic rainboom,' which is basically flying faster than A LOT of the pegasus and going so fast she leaves behind a rainbow. But a cutie mark can also represent a hobby. I can't think of a specific pony right now, but an example would be a writer pony, who's talent is actually art though they enjoy writing, so then their cutie mark would be, for example, a book and a paint brush to resemble both their talent and hobby. Some cutie marks have nothing to do with it, and are simply chosen because of the pony's name. Derpy hooves, another pony, her cutie mark is bubbles. No one has any idea what her talent is, but they would assume it has something to do with muffins. [ she loves them ] But no. It's bubbles. So that also shows a cm can mean, absolutely nothing at all.
And as for the style, it's perfect, and Periwinkle Feather for a name? Idk, just something i thought of.