I like the way her tail is billowing out as though caught by a powerful wind. Except...hm, that doesn't seem to be the case for her bangs or mane. Oh, I get it. That would explain her facial expression. Beans night.
New theory: Overwhelmed by the new, sudden changes and the loss of her friends, a hundred years later (Yes, I know it was said that she won't outlive them, but I'm sticking with my first thought of her immortality) she goes mad with frustration, banishes Luna and celesta and takes over Equestria. Under her rule, it is driven to destruction.