Buffy is patrolling Commissary. That's pretty much her entire job for the moment. She makes a round: 14th floor, commissary, 15th floor, back to Commissary. It's during one of these rounds that she sees Derek in the commissary. In light of everything that's been happening, she really isn't terribly chipper. She's wearing an orange jumpsuit, but then he knows that.

"Hey," she says as she approaches, a tired, serious look on her face. "You okay?"

Because there were the weird dreams then the shooter that they'd been protecting had been assassinated. On top of all of that, she hasn't actually seen her best friend much the last couple of days. It's a lot.