Halftone is a way of reproducing an image through the use of dots or spots, varying in size, shape, or spacing to generate a gradient-like effect.
This Snack involves your brain, your eyes, and geometry. Your brain is built to recognize patterns. A pattern that looks like a face is a high priority for your brain—recognizing faces is important to our survival. The area of your brain devoted to facial recognition is known as the fusiform gyrus.
Up close, the spots are projected onto the retina, at the back of your eye. At a close distance the spots may look like, well, a bunch of spots!
As you move farther away from the picture, the image of the face becomes smaller and you become less able to distinguish between adjacent spots. Because of your eye’s resolving power, you perceive shades of gray rather than spots and blank spaces.
As a result, your eye–brain system is better able to recognize the smaller, slightly blurred image at a distance as being a face more easily than the up-close—but therefore larger—pixelated image.