I had absolutely no idea discord could do that with his eyes. Pinkie Pie has definitely been giving this guy WAY too much sugar.
Besides the above, and Chrysalis expression (well drawn by the way), there are two things that make this picture downright hilarious.
1. It is very hard to determine whether or not Discord is what tvtropes calls "bullying a dragon" (the definition of "bullying a dragon" is in the below link). This is because, while Chrysalis can technically suck him dry of his life force/love, Discord could technically constantly change her into all kinds of crazy things (this would definitely mock her as a changeling).