@PonyPon  
Maybe. Both shows do like their symbolism.
 
Her real cutie mark is still normal though, I just checked.

@Hateot  
So she’s all good now, and because of Twilight I guess?
 
And this means red was the good side?

@FlonnesIkramant  
Interesting thing note is that EqG usually takes place between seasons, so maybe something happens to twilight in the S7 finale. Though that’s still a little too far fetched

Hmm, the Sunset half is missing the Yin-Yang symbol.

Merging CMs seems like it should be a way to represent ships.

 
Twilight’s cutie mark has red and white while Sunset’s book has two different colors, a different shape and no stars. On closer inspection it doesn’t look like twilight’s cutie mark even if that was the intention.  

foreshadowing… a fusion?

It’s just Twilight and Sunset’s marks combined.

DBZ fusions confirmed

Seems like a mix of Sunset’s and Twilight’s.

Yep, it’s Twilight’s and Sunset’s combined.