Take one look at this Pixel Mirror and you instantly get it. An image is transformed into a low-resolution, pixelated, version of itself. The actual product is meant to be worn as a necklace (retailing around ~$120USD) but this article wisely points out that its actually an incredibly useful tool for artists as well, reducing images to their simplified versions.

Do click through for more examples. They're all quite neat but the cloud just summed it up perfectly for me.