At its closest point, Juno flew so close the Great Red Spot that it couldn't capture the whole thing in one view. The image below shows the approximate angle that JunoCam was able to see at that point.
Making the task even more challenging: The probe zoomed by at about 34 miles per second. That's speedy enough to traverse the continental US in a little more than a minute.
As a result, JunoCam strafed the planet with a series of images.