That duet with Cadence was pretty fcking epic, I'll give you that. Hell, I was sitting there thinking "this sounds as powerful and riveting as something you'd see in a Disney movie." But even at that, nothing, and I mean nothing can top 'Smile.'
You've got a great human Chrysalis here; the sharp angles and harsh features, the sickly colors, and the innovations taken in her attire to reflect the characteristic pitted chitin are all done great. The only thing I would've recommended would have been to make her skin a bit more diseased in appearance, like giving it the slight shade of bile green or pale yellow usually seen in vomit, more maybe even a touch of fuchsia.
This day has been just purrrfect The kind of day of which I've dreamed since I was small Everypony I'll soon control Every stallion, mare and foal Who says a girl can't really have it all? *evil/cute laugh*
Even knowing that making her holes a costume is an awesome idea, and believe, as a guy who like this kinda of thing in fashion, I loved it, I still think you could do a version with real holes in her, making it a bit disturbing, if you know what I mean. All the ponies that were there(and Spike) make a really surprise face after saw her real form. Well that's it, keep up the good work (: