Whoa, they’re palette swaps.

Haha! Rearing!

@Rainbow Dude  
My head-canon Cutie Marks for them;  
Dinky Hooves: a chocolate-chip muffin with some sparkles (Dinky is momma Derpy s’ little muffin!)  
Tootsie Flute: a pink flower, duh, it’s her canon one! (little Tootsie Flute always makes a flowery tingle when she smiles!)  
Ruby Pinch: three pink rubies, CM is a recolor of Amethyst Star’s. (Ruby Pinch is considered the “gem” of the family!)  
Alula: “Ambox Speedy Deletion” sign. (Alula likes to give a lot of uncompatible informations to the same people at the same time, and made everypony glitch so hard once, she became the Princess of Errors, sprouted an horn and was now an Alicorn known as Princess Erroria.)  
Tornado Bolt: A black lightning bolt with an yellow lightning coming out of it (Tornado Bolt flies so fast and makes lightning go from the clouds!)  
Cotton Cloudy: A white cloud and some snowballs (Cotton Cloudy loves to make sculptures with snow and clouds!)  
Noi: (Noi s’ Cutie Mark seems to change randomly, imitating other ponies. How does she do it, does she have an hidden secret?)  
Piña Colada: Palm on an island (Piña Colada likes to brew pineapple juice, and hopes to make it a business when she’s big!)  
Half-Note Aura: Two lavender ballet shoes (Half-Note Aura loves to dance more than every other thing!)

@rafasilva  
@catamaran  
Yeah, the incidental background fillies don’t have consistent cutie marks.

hoofy-kicks is my instant-happy button for the day.

also HOOFY-KICKS HNNNNNNNNNNNGGGGGGGG

@rafasilva  
yeah, but look at that cupcake cutie mark. doesn’t correspond to any named filly on the wiki.
 
i got tootsie flute / petunia.

@rafasilva  
And Tootsie Flute, both suffering from No Identity syndrome.

Isn’t that Ruby Pinch?