More easily than the stage manager of the real theater he can choose actors whose natural build and physiognomy fit the role and predispose them for the desired expression.
The drama depends upon professional actors; the photoplay can pick players among any group of people for specific roles.

They need no art of speaking and no training in delivery.

The artificial make-up of the stage actors in order to give them special character is therefore less needed for the screen.

The expression of the faces and the gestures must gain through such natural fitness of the man for the particular role.

If the photoplay needs a brutal boxer in a mining camp, the producer will not, like the stage manager, try to transform a clean, neat, professional actor into a vulgar brute, but he will sift the Bowery until he has found some creature who looks as if he came from that mining camp and who has at least the prizefighter's cauliflower ear which results from the smashing of the ear cartilage.