From a strategic standpoint, why are the playful actions of raskolnikov and razumihin upon entering porifity's room effective?

From a strategic standpoint Raskolnikov wants to appear to Porfiry as a fun-loving, spur of the moment, easy gping guy. To appear this way gives him a better chance of endearing Porfiry and in turn acquiring his help in getting the items from the pawn broker. He has ulterior motives for everything.