What's the Boundary Object Conversation?

"I no longer do my release planning this way, because i think it puts way too much emphasis on priority and not enough on value," he says. "If we're doing this in person, a that brain storming starts to slow down." He's trying to get every story to be expressed in terms of the business benefits it provides. 'The other thing that's neat about working in person is that little conversation knots will form'