This move is a good way to exploit a defence that is lazy to shut, specifically the link and winger.
The first phase involves the right mid targeting his opposite number and making sure that he's moving infield. The left mid runs line expecting to be the next dummy half.
Key points:
The right mid that dumped on his opposite number splits left. This will draw the right side of the defensive line left.
The dummy half passes to the right middle who is running a short line which will draw the right link. The dummy half then wraps the right link creating the overlap.
Scoring opportunities
Right link is slow to shut: Score inbetween defensive right mid and right link
Winger is slow to shut: Right link offloads to the wrapping dummy half to score
Both link and winger shut: Quick through the hands to the winger