Stop bugging me

Now THIS is a fight I wanna see go down! So aside from the lighting and what really intensifies this drawing is the facial expressions both characters give. Chrysalis presents wickedness and vanity, while Zecora displays vengeance and aggravation. You can tell that they are both prepared to battle, they just both have different attitudes towards the dispute. Now as well-drawn and well-colored this piece is, I will say that there are a few aspects that confuse me. For example, what does she mean by "say 'cheese'"? Is that suppose to indicate that she's about to flash her with her horn, and that she should prepare for the brightness? Also, I feel like the background should be more detailed. The bottom has all these different shapes of green, but the top has one solid color. The background shouldn't be too distracting from the subjects, but why is the top left with practically no design? I guess those are just personal gripes that I don't understand. All in all, I'm very impressed with this cartoon. Keep it up, and I wish to see more from you soon!