That hair though

I was going to ask what the design choices were based on, but luckily the artist elaborated in the dA description:

"Major detail:
She does not like being called a Dwarf.
She wants Earth-chan to notice her.
She is older than Earth-chan by .1 billion years
She looks like an 11 year old because she was named by an 11 year old.
Legal loli

Short details:
The character is short because dwarf planet.
Hair covering the eyes because is the only "planet" in the solar system not to be seen by the human eye.
She wears an artic jacket due to extreme feeezing temperatures on the planet's surface.
Heart on the coat because there is a large heart on pluto
5 fluffy buttons to represent the 5 moons that orbit the planet
Light purple and red hair. Based off of the colored image of the planet.
She wars ear muffs that have the PL monogram or "♇"
She has hair that wings out to form what look like dog ears (almost) to represent the Walt Disney joke of pluto the dog"