This drill is designed to be a Power Play passing example. It fits an overload style power play, offering an option for scoring opportunity. There are many variations of options that could be built out of this. 

Focus is on quick passing. Tape-to-tape. Players need to be taught the details of patience in this drill, pertaining to power play scenario. Don't just pass to the next spot because thats the pattern. Talk to them about what they are trying to accomplish. Draw the killers towards the puck, make them move and open lanes, and have timing in their drive to the net. 

Passes to the middle are equal to using a bump man.