I have not included any screenshots because Simple Menus does not have any admin screens of its own.
The input elements for selecting the secondary menu are added via hooks in the admin interface. Other plugins use those same hooks to add interface items as well. For example, every SEO plugin is going to add an interface item to the term edit screen using the same hook Simple Menus uses.
The probability that my screenshot is going to match what a prospective user is going to see in their admin area is small which would cause more confusion than it would solve.