When Canadian teacher Braden McKinnon was doing arts and crafts with his students, creating an optical illusion was the last thing he expected to happen.
His class was celebrating Remembrance Day (a Canadian commemoration of military service) and, as tradition has it, they were crafting red paper poppies for a decorative wreath.
McKinnon quickly drew outlines of the poppies for his students to cut out, and afterward he noticed that the edges of the flowers looked like they were overlapping – even though they were drawn separately.
Do you see the overlap? Try to look quickly at the image, without focusing too hard.
Puzzled, McKinnon posted the image of the poppies to Reddit, where it has since gone viral with 124,000,000 clicks.
A few Redditors surmised that the reason for the flowers’ trickery is something called the Gestalt Continuity Law of grouping, which explains the human tendency to form patterns and perceive things as a single, overlapping object when they’re positioned next to each other.