This image is unbalanced because the subject of interest is placed in one of the corner on an empty background.
This image is balanced because the subjects of interest (the three kids on the left) is balanced by a smaller subject (the walking kid on the right).
This is an balanced image because the image is divided in two by a focused part and an unfocused part, which balanced out the image. There is also a small ball in the right side, which balanced out the fire alarm, the subject of interest.
This is an unbalanced image because all the subjects are placed in the right middle part of the image.
