Something I love about art is that it can be used to convey the entire spectrum of the human experience. I also enjoy art that makes a social commentary without saying a word, as some of our contributors have posted.
Here is an especially haunting, very recent piece in an exhibit "Dismaland" (a riff off Disneyland), located in the UK (*WARNING* Some may find this too disturbing):
This is a commentary about the death of Princess Diana. In the "theme park's" brochure, the caption says, "Step inside the fairytale... and see what it feels like to be a real princess."
I recently saw a live-action run of this piece and it's set up so that the mannequin photographer's "cameras" are going off constantly, creating constant, blinding flashes of light, in a parallel of Diana's car crash where the photographers continuously photographed the scene, but not a single one stepped forward to give aid or medical assistance.
I find this piece to be thought-provoking, haunting... and in some ways, even scarring.