I could but it's easier if you click here.
http://auto.howstuffworks.com/torque-converter2.htm
No it isn't always revving higher. The best way for me to explain it is like this. Imagine you have a manual transmission car. You have your foot on the throttle with the clutch in full and are revving to 3800 revs, just before 2nd turbo time, then it is up to you how quickly you want to take off. If you want to do a super fast launch then you would let the clutch out quickly, if you want to pull away normally you let the clutch out gently. With the hi stall the car won't start moving until 3800 revs where as before it would start moving at 2200 revs and be bogged down in that horrible sluggish part of your torque curve waiting for your turbos to spool up. Once you are going it is like normal again.