Regarding "Tumblrina," I wonder if she was supposed to be a reference to someone in particular, as she appears out of nowhere, says "Oh my gawsh! A sale?!" and then her cutie mark is herself inside of a group of stars.
Her mane is also markedly different from other pony manes, so I just wonder.
If it's a reference, I'm missing it.
I was wondering the same thing. Maybe she's just a pony celebrity. I liked her.