Everyone in your department's gathered for a meeting, when someone points out that there's no coffee. A meeting without coffee is like a wedding without an open bar, but the secretary's on the phone with a client and the unpaid intern is out in the woods somewhere looking for leprechaun gold for the amusement of the rest of the office. So the task inevitably falls to whichever woman happens to be closest to the coffeemaker, regardless of whether they're the newbie or the highest-ranking person in the room.
It's called office housework, and it also includes meeting preparation and notes, party planning, convincing people that the party won't be a tedious waste of time, etc. Basically, it's all the crap that no one wants to do but is absolutely essential for keeping an office humming along smoothly. The problem is that women get stuck with it disproportionately, even when their pay grade should put them far beyond menial duties. Yeah, that murder trial tomorrow is important and you should prepare for it tonight, but Steve's birthday cupcakes aren't going to bake themselves!
"Please try to save one; my client's going to need some cheering up when he gets the death penalty."
It's a subject no one wants to put any thought or effort into, so women get stuck with it by default because we still see housework as a woman's chore ... even if said woman could be making a few hundred bucks spending an hour with a client instead of explaining to her underlings that eight cheese dips and 12 deserts don't constitute an appropriate potluck.