Once Google’s AI thinks it has a good understanding of what links together the images you’ve uploaded, it can be used to look for that pattern in new uploads, spitting out a number for how ...

Hidden within the design is the number, challenging your perception and focus. Discover why some spot it instantly while others struggle, and test your visual skills with this viral brain teaser.

Spoiler alert: the odd number is 15, and it appears subtly in the middle of the image, among the consistent “12s” and “21s.” It doesn’t jump out immediately because it's designed to blend in with the ...