Rhythm

That is a nice exemple of rhythm. There is a good balance on the image and the spiral with space between the 'arms' give a rhythm to it. Also the color becoming lighter from edge to the center.

Balance

We have three different elements of varied sizes in front of the mask. The mask is centered, however the three elements are not, but they are displaced creating  a visual balance.

Unity

It is interesting how the unity works in this image. First of all the circles create a nice background with a specific space between them. Then the words shape a not easy triangle.   

Variety

This is a poster by Giovanni Pintori. (Megg's History of Graphic Design, page 413, image 20-3)
The parts of the 'body' have different shapes and color. There are lines overlapping others.