I find portrait photography to over lap with architecture photography. I think one key is to keep the back of the camera vertical for a natural look.
1) Our eyes see a building as having parallel sides (assuming it's not a Frank Gerry creation). But, we all know that if you take a fixed back camera and point it up at a skyscraper, the lines of the building will converge on the film. Our brain compensates to make the lines look parallel, the camera does not. I think the same thing happens with portraits, especially full length portraits. Our brains tell us that the subject is standing straight even when looking down from eye level, which in my case is about 5' 6" high (I'm 6' 2" tall). If I put the camera at my eye level (or the model's eye level if the model is shorter) and angle the camera down, the human form gets distorted on the film--a distortion our brains override in every day life. Consequently, as a general "rule", I try to shoot with a vertical back.
2) For full length portraits, fashion work and nudes, I like to center the camera on the model's belly button. This is just slightly above the mid point of the body (and it follows the golden mean very nicely). I think it gives a natural look to the body without giving too much emphasis to the legs. I have the model lengthen her neck and tilt her head down to look at the top of the lens to avoid the double chin and up the nose shot. I tend to do the same for closer portraits--figure out what I want in the frame and put the camera position just slightly above center.
3) Remember that things closer to the camera will be exaggerated on the film. I think this is part of your problem with the setting shown in the drawing. The feet are closer to the camera than the model's body and head, and therefore exaggerated. When drawing the model, the artist can use foreshortening--not really possible with a camera. I'd change the model's pose.
Here is and interesting experiment for you to try: Photograph a mannequin or a model. Start at eye level with the camera tilted down. Take another at eye level with the camera back parallel to the standing model (use front fall to get all the model on the film). Take several more exposures moving the camera lower, until it is below waist level. Look at the final prints and decide on the most natural looking. I have done this (back when 4x5 polaroid was around), and I decided I like the look from belly button height the best. Your milage may vary.
Another interesting thing to do is to page through magazines and books and look carefully at the photographs. Place your finger in the exact center of the photograph. If there is no obvious or deliberate distortion (less likely today than twenty years ago), then your finger is probably at the level the photographer had his or her camera.