WOW i love this pic two villans who i just love the Great and Powerful Trixi and Queen Chrysalis (the changling queen i just love cause she is just evil and noreasons just evil i love that type of villan) well i can tell trixi has overstayed her time in ponyville when a badass villan shows up in her magic mirror (mirror mirror on the wall YOU WILL DIE B****) well i can tell that trixi is scared out of her mind by a weird... ponylike... thing that just shows up in her mirror well i recommend you look at this.
Your vision for this is amazing. Chrysalis is a fairly new 'villain' to the world of MLP:FIM, and the idea of combining her with an older 'villain' is something I've seen talked about but not really done until now. This also applies for the originality of the piece.
For the technique, I think this is fantastic. Chrysalis looks like she just walked right out of the show but Trixie is clearly done in your own style. Yet somehow the two look perfect together, even though I think a more consistent style of either show or your own would have been better. I also really like the torn and peeling wallpaper, the semi-broken mirror and how ragged Trixie's clothing looks.
The aforementioned words go towards the impact as well. When I first saw this piece I wasn't quite sure what to think and had to stare at my screen for a few moments to take it all in then try to wrap my head around just what I was seeing. I've been almost where Trixie is before, so I know how absolutely frightening it can be to have this feeling that there's something inside of you and it's not you but it wants to take over, and all you can do is stare at yourself in the mirror for a bit and hope you find yourself staring back because if you don't the fear just gets worse.
Overall I really, really like this. I docked you a bit for technique because, as I said, there's a mixture of trying to imitate the show's artwork and your own style here and while for this particular picture they work well together I don't think it would for anything else. Other than that I have nothing to offer, you've done a spectacular job.