A chart should represent what you desire in a waifu as a whole. You aren't offering your affection to each individually. They all have elements you find enjoyable, whether physically or emotionally, and the chart create something in the creator's mind greater than the sum of its parts. That's why, in non-memeposts, charts tend to have a trend. A specific throughline that shows the personality of the poster more clearly, through what it is they desire or find desirable.