Shading has improved a lot here. I also notice the skillful application of some reflected light, and, although seemingly sketchy, I like the way RD's wings were illustrated. I feel like I fill in most of the detail automatically as I look over it. As to Twilight, I really like how expressive her walk is and the stylized flatness of her tail. Last thing I literally just noticed, impressive job of lapping RD's hair in a 3 dimensional fashion. Normally it's illustrated exclusive to one side or the other but you managed to naturally lay it down her back.
Although I liked Twilight's tail, I do not like RD's. It's fat and voluminous like a balloon as opposed to her mane which is far more naturally. The other thing that strikes me as odd is her wings. The angle of her entire body is slanted ever so slightly towards the foreground but her left wing drops below her right wing. It's inconsistent with the angle and appears odd although many might not immediately point it out. Twilight's expression isn't sold very well either. I can see that she's biting her lip but at the same time compared to how expressive the rest is, it's not nearly as well exaggerated. I also feel like the shading on her legs is inconsistent with the shading on RD. Light appears to be coming from the top left and top right but on Twilight it appears to only be from the top.
All in all, another good job. I apologize if I seem overly critical.