This odd set of symbols appears 
on a vintage pocket watch fob.

This copper-colored 3/4" disk has two sides, and can rotate freely in its half-moon frame. If you stare at the disk while spinning it quickly, the odd markings on both sides combine to form the symbols of Freemasonry, including the Masonic square and compasses with the letter "G" in the center, a trowel, plus another symbol I can’t identify.

The result of staring and spinning.

Two Altered Visions, Flickr>>