the Mask

It looks like a mask, a double mask maybe, which hide someone's face but this is the spider's back. The figure on its back mask out the body misleading creatures. It's even more interesting that it has the resemblance of an angry human face.

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Nikon D70 with SB-800 flash set to Auto @ f/32.
Flash was off camera with Nikon AS-17,
45 degress from and above camera position on the left side.
Vivitar 100mm f/3.5 AIS lens at f/22.
Shutter speed at 1/200sec.
Camera on Manfrotto 190CL tripod.