Using a remote flash unit I took the first of these images with the flash unit directly above the subject. This light is harsh and flat and tends to wash out details. It also creates strong shadows.
To the flash I added some tissue paper by way of a diffuser. This created a yellow hue but also softened the light and the shadows created. It also prevented the washing out of detail.
I then retook the same images using the same combination of diffuser and without, this time with the flash situated to the left of the subject. the same effects were seen but the effect on the shadow was more pronounced.