I don't know if anyone will need this note, but English isn't the first language of some who read this, and it was an odd choice even if it is, soooo... Here we go:
Ducks quack. Diane's duck-ing. So... Quack.
You may now applaud.
For a long time now, I've thought that, if this comic were a Roleplaying Game, Diane would be a "rogue" class. This means good at dexterity, acrobatics, charisma, smooth talking, sneakiness, etc.
Granted, I don't believe a rogue HAS to be good at all those things. For one thing, a player could intentionally make a bad rogue. It's just something I think about when I consider what Diane should, and can, do in certain situations.