Setting up lighting for a portrait can be quite a complex task. If you, like me, are using small strobes which have mo modeling light it is hard to predict what will be the outcome of each lighting array.
There are however some basic lighting schemes, kind of a starting ground for new portraits. Of course, once you lay out the initial lighting you can change it, move it around and use modifiers to soften or restrict the light.
Wouldn’t it be nice, though if you have a magic card that will show you what will be the final lighting of almost every lighting scheme? I think it can be pretty darn cool.