A work of art

A tiny but dignified old lady was among a group looking at an
art exhibition in a newly opened gallery. Suddenly one
contemporary painting caught her eye.

"What on earth," she inquired of the artist standing nearby, "is
that?"

He smiled condescendingly. "That, my dear lady, is supposed
to be a mother and her child."

"Well, then," snapped the little old lady, "why isn't it?"