Randomness: our brain deceive us

Here two points distribution : one is random, and one is not:

Which is which ?
The thing is that left image is not random, and right is.
Sean Carroll from Cosmic Variance write:
“Humans are not very good at generating random sequences; when asked to come up with a “random” sequence of coin flips from their heads, they inevitably include too few long strings of the same outcome. In other words, they think that randomness looks a lot more uniform and structureless than it really does. The flip side is that, when things really are random, they see patterns that aren’t really there. It might be in coin flips or distributions of points, or it might involve the Virgin Mary on a grilled cheese sandwich, or the insistence on assigning blame for random unfortunate events.”