People sure love playing ball games with their pets. Well, now it’s your turn!
As you can see, there is a group of pink balls that form a circle above.
Stare at the black cross and only the black cross. Really concentrate, then wait.
Most likely, you saw a rotating GREEN ball passing through the pink ones. If you stared long enough, you probably even saw those pink ones disappear completely!
This is yet another example of how our minds can really play tricks on us (check this out too). There is no green ball and the pink ones never disappear.