Definitely looks like she's in the middle of some kind of action. PEW PEW PEW But she's using a shield made of tiny bubbles to deflect all the magical bullets.
Annnnd... I've just thought of an idea for a fanfic. Derpy masters the art of using bubbles, for both offensive and defensive purposes, which comes in very handy whenever she bumps into trouble. She somehow decides to become a guard for Celestia, and eventually becomes promoted to rank General. This is not any other lovey-dovey story. This is a story about a pegasus, a friend, a soldier, a mother... somepony who became more than anyone could imagine. (Whether that eye-patch is from an injury or to make her look more intimidating, is up to the author.)