Snap is a very different form of Captcha but its intentions are still the same. It still essentially wants to figure out if you are a human or a Bot.
This prototype chooses a category and asks the user to select a number of images that match that category.
Accessibility issues have been considered allowing it to be used by most users with disabilities via image descriptions and access keys. This isn't a perfect solution and I'm not sure there will ever be one but it provides an interesting and slightly addictive solution to a problem that plagues the internet.