The host asks you to count the number of red cards in a deck, and she promises you that the results of her video will demonstrate your attentiveness—or lack thereof. It seems easy enough, right? Find out for yourself. Don't keep reading until you've watched the video.
The key to the video is that you're supposed to be paying attention to more than just the cards. What the video illustrates is how difficult it is to focus on stimuli outside of those associated with a prescribed task. Even so, many people in the comments section are claiming that they identified the trick early on, with some even forsaking the card-counting task to watch the background for changes.
Are you task-oriented, open to everything, or somewhere in between? How you respond to this video definitely illustrates your attention style.
Screengrab via BuzzFeedBlue/YouTube.