Whenever you show a group of related items, it's important to show 1) that each item is different and 2) that items share some commonality that places them in the same conceptual group. These contradictory goals are most easily achieved by having the individual items be noticeably similar, but visually...

A previous post explained symmetry and asymmetry, the yin and yang of effective design (different, but inseparable). Symmetry helps the viewer group items into a "box" (category). Asymmetry provides a touch of visual interest. Take a look at a screen capture of a web page with several images. Each image...