Jono Lee, a visitor to Bernal Hil and the Dominion of Bernalwood, posted this stunner on the Instagram over the weekend. He says:
The world is just one giant gradient.
We heartily agree (even if we’re not quite sure what that means).
PHOTO: @jobosapien
Bernalwood 
I must strongly disagree. I think there are at least two gradients.
But, of course, no more than three.
The meaning is obvious.
I agree with withak30 and I believe he means that because the world is round even if it looks flat it is actually a gradient hill.
If only that were true. Unfortunately, often times there is banding.
He’s referring to the gradual change in hue and brightness in the sky from the top down (or bottom-up if you prefer). Photographers and graphic designers call that visual transition a “gradient”.