I don't think the expression on her face is too much as some people say I would say maybe in HIS eyes, she looks that much disgusted because he is so hurt and her rejection feels so hard to him. Sometimes, people's expressions seem harder than they actually are if you are hurt. But that's just me and the way I would see it Anyway, epic comic
I think its because this is supposed to be young Celestia where she is arrogant, mentally selfish, and judgemental. From what I've seen from her fandom, she is young, already mastered her power of raising the sun, teaching/helping/raising filly Luna, and not yet or learning to be a ruler.
And that her hair has it's "flowing magic" effect when she reaches adulthood which is why young Celestia is always seen with a normal pink mane loolz.
The background detail and the framing is incredible. Although I do have to say I liked Celestia's expression in the first draft better. Here she just looks pissed off. In the other she looked shocked and revolted, which I thought worked better.