Perry is so good at using his body and stick and skates to get the position he wants in front of the net. Doughty is a husk at this point, but Perry's move right before the puck gets sent in front is textbook.
Stick check on Doughty's stick, giving Perry's stick freedom to move and pinning Doughty's to his body.
Before Doughty can lift Perry's stick, Perry body-rolls around both sticks, which now frees up both his stick and his body, and positions him inside and right of Doughty, essentially giving him free access to any pucks that come to that side of the net.
This forces a defender to come down and help when the puck goes in front since Perry would have a ton of leverage on Doughty, and that defender now has to leave one of the top 5 goal-scorers in the world alone to clean up a rebound.
Perry is known for being dirty and grimy in front of the net, and certainly he can be, but this is just good, clean, textbook manipulation of a defender and creation/protection of important space in front of the net.
Suck it, Doughty.