That iconic picture for the Return of the Jedi poster? Those are Lucas’ hands holding the light saber.
This is probably a detail that seems important to the artist, but is rarely noticed by the audience. The grip in the poster seems uncomplicated.
The hands grip the handle, one above the other, and it seems anyone could have done it. Many years have passed, and we can only guess what was really happening here. It could be more accurate to say that Lucas might have trusted Hamill to get the grip right, but wasn’t sure if his hands had the right look to do it.
Among those who make such images, the appearance of body parts can be very important. Hands become symbols of strength and bravery, running feet become embodiments of desperation and determination, and a captured glance becomes the distillation of passion.
Some people have big hands. Others have thin ones. It doesn’t mean much unless you play piano, or unless you’re trying to embody strength, bravery and fantasy for generations to come.