Emphasis

In this ad the shape of the rose will dominate because of it's colour uniqueness. The colour contrast of red against the gray scale background makes the rose more exaggerated in colour.

Propotion

This ad creates interest and drama by contrasting the large cellphone with the small shapes coming from it. The large shape makes the little shapes stand out and adds proportions.

Balance

In this ad you can find the visual balance with the symmetrical balls. Thats is why this ad is decirbing the princple of balnce.

Rhythm

This ad creates the illusion of movement by the repeating circle shapes. It seems like the shapes are flowing in the air because there is so many of them and they are scattered around. 

Contrast

This ad creates interest and drama by contrasting black with white. The white really stands out against the black background. When your eye glances at it there's nothing else to look at but the white object.

Unity/Harmony

This ad creates interest and drama through the repetition of the water bottles in a order. Organizing these shapes create a pattern. This pattern creates unity and harmony.