Suspicion

Eyes so turned than they show a large glint of white suggest one of the subversive emotions—suspicion, jealousy, flirtation, or fear, and they should not be so displayed unless some such thought is meant to be conveyed (Figure 16). In portraits it is usually essential that the eyes be shown; but in pictures with the emphasis on the plastic qualities, particularly in nudes, an advantageous impression of impersonality is gained by downcast eyes.
William Mortensen, The Model: A Book on the Problems of Posing (1937), p. 34
Corpus Delicti
Generally the inexperienced photographer is embarrassed and surprised on discovering how unmanageable an apparently compliant model can be. Like someone who has incautiously committed a murder, he is left with an awkward corpus delicti on his hands, a certain amount of flesh which he must dispose of gracefully, but which, in his mounting panic, becomes increasingly unmanageable with his every desperate effort to do something with it.
Perhaps he has heard that natural poses are the best. So he may attempt a laissez-faire attitude and let nature take its course in the matter of posing. But he soon learns that, photographically at least, Nature is an unpleasing, stupid, lumpy, blowsy wench. The artist in any medium is unhappily compelled to cope with the damnable perversity of things, but none so much as the photographer is aware of the utter uncooperativeness and the implacable stubbornness of Nature. The painter may adjust perspectives and warp arms and legs into attitudes that are more becoming or compatable with his design. But the photographer must take things as they are. The arms and legs that he deals with are flesh and bone, and are uncompromisingly unmalleable.
The photographer with a model is a Creator with a little bit of Chaos. He must learn the Word that will give it form.
William Mortensen, The Model: A Book on the Problems of Posing (1937), p. 16
Lay Figure

Mortensen designates Figure 1 as a “lay figure.” For the purposes of his modeling book, the live model Mary Jones will be regarded merely as a lay figure—“A more delicately articulated lay figure, no doubt, but needing just as much mechanical adustment” (20-21). You see, “Mary is just as disorganized physically as the manikin here illustrated. We are not for a moment concerned with what Mary thinks or feels, but merely with the mechanical adjustment and plastic relationships of her articulated members” (21).
The difficulty I have with this is that I can’t help but thinking the poor “lay figure” has slipped upon the ice. It appears to me that something is broken, so she might have great difficulty articulating her members.