Unless I am misunderstanding, it seems to me that the work queue is actually a stack. Specifically, the "cont: 101-200" work was added to the work queue before the "cont: 51-100" was added, and yet it seems that "cont: 51-100" is scheduled to be run before "cont: 101-200" (I could be wrong here, since I'm interpreting this diagram as Thread 0 pulling work from the bottom of the queue, and not the top. If this is the case, then the queue is in fact operating as a stack and not a queue...

Never mind, the next slide clarifies everything!