In the flattened top, she saw the bald bony forehead.
That little suzhi (loop) was the socket for the eye. The empty complimentary space invisibly completing itself to form the other eye place.
The curved bottom looked like the toothless lower jaw of a grinning face. She finished the upper jawline with her mind's ink.
The Tamil letter ஒ ("oh") always had reminded her of a skeleton head.