Visitor side
What the visitor sees
At rest, the component shows nothing but a checkbox: Click here to confirm you are not a robot. No image is loaded until the visitor has shown intent — the page stays light for everyone who submits nothing.
On click, a strip of six symbols appears, drawn side by side. Only one of those symbols occurs a single time: that is the one to point at. Shapes are drawn from a repertoire of a dozen simple silhouettes — drop, moon, bolt, arrow, star, pentagon, shield, leaf, house, heart, triangle — traced on the fly, never served from a stock of images.
Two links sit under the challenge: Another challenge, to draw a fresh one, and Written challenge, which switches to the accessible alternative.