I don't know the original sequence of these images but I've placed one last because it's my favourite. The combination of front and rear views utilises the good, old, Royale, mirror technique. The lower viewpoint makes the model's proportions look more balanced and natural and the reflection of the lower body gets an extra lift from the angle of the mirror. You can see below how much the impact of the image is enhanced with more modern, tighter cropping.
For sharp-eyed pornsters, the 'bulge' reflected in the mirror now appears to be pointing directly outwards towards us complete with slit. I'm not 100% sure that this is an original effect but it's pretty convincing. In Royale's time, pre-Photoshop, this would have taken some doing, either by manipulating the original lighting or by rephotographing an altered print or negative. For other examples of hidden eroticism click here.