Here is information from the Help on how the entry point is handled for Smart Shapes. Maybe someone else in the forum will have an example of where or how it is used in their application.
From Smart Shape Help document
Select to indicate that this Utility shape is an entry point, which a user can return to using the breadcrumbs control or the standard flow action Previous. The default is cleared.
Because a utility shape presents no user form, if a user clicks a breadcrumbs control to return to this entry point, flow processing resumes and pauses at the next assignment or other shape that requires user input.