This is a (poor) photo of Nat (left) and Paul performing the "Romance for Men" sketch at the Albert Hall, Town Hall Bolton. Nat plays the urbane and sophisticated one (obviously he is acting) and Paul plays the pleb (obviously he isn't acting).
Nat is telling Paul: “Next you need to alter your posture. Head forward, shoulders back, stomach slightly distended, buttocks protruding ever so temptingly, knees bent, toes slightly inverted.” You can read the whole story by clicking on Stories.