One aspiring artist to another. I'll give some speculation on what I think can use some work. Take it with a grain of salt though, I'm not a seasoned critique.>>1083>>1087>>1084
The necks seem a bit long in this cluster. (I included image with neck proportions) I also see some inconsistency in the eyes. Twilight's eyes look a tad large, Fluttershy's left eye looks smaller than the right though closer in perspective.
Something I'd recommend is when you're drawing them from that angle, draw the eye furthest from the viewer along with the snout in one motion, I'll demonstrate in the pic here with a screencap reference>>>1469
I also see a tad awkwardness in the mouth's. the mouth should always connect around the snout when you're looking at the pones from a side view.
I like the pink inner-ear you add, but the shape of the ear wrapping on the head looks a little stiff. Maybe give your arm a bit more freedom to swerve when you draw them. Also the end of the ear where it's closer to the side of the head should be ever slightly more thick as it tapers down. Try seeing what letting the ear lineart trace over the head as well instead of the head overruling.
I'd appreciate it if you help me out as well sometime. I got a similar thread here:https://www.ponychan.net/fan/res/1521.html