apotropaic

In an art history sense, this word is commonly used to describe an image that makes the viewer feel uncomfortable and want to turn away, as in Picasso's "Les Demoiselles d'Avignon"

This differs slightly from the definition you'll find in a traditional dictionary, which is that it is something to ward off evil or bad luck. It is derived from the same term apotrepein, which means "to turn away, avert"