The King George statue is symbolic of Great Britain's ruling power over the colonies. The statue is a big "golden" statue of King George riding a horse. It is an incredibly powerful-seeming statue that commands respect, yet Isabel notices that the statue commands more respect when the sun is out. The gold shines far brighter and far more powerfully when the sun is out. When the clouds are out, the statue seems far less impressive. Savvy readers will see that this particular observation is quite symbolic. When everybody loves, honors, and supports Britain and the crown, it shines quite brightly. When the clouds of rebellion come out, the king and his power look far less impressive.
The King George statue plays a prominent role in chapter 20, and the Patriots have a great time pulling the statue down and chopping it up. Isabel is shocked to see how easily the statue breaks apart. She knows that gold should not crumble so easily. When the patriots tear the statue apart, we learn it isn't actually made of gold. The statue is made of lead and "covered with gilt paint." It was made to look imposing and powerful, but it is actually nothing but a cheap fake. The Patriots see the actual King George in exactly the same light.