When you work in Notes, you work with workspace, databases, views, documents and fields. Sometimes the documents are in read mode, and sometimes they are in write-mode.
A Notes Addin Menu knows exactly where you work, and what edit-mode you are in. In addition addin menus knows what field you are in when you are editing a document.
If you are working in a view, a addin menu also knows something about your current document selection. Have you selected multiple documents, or are you just working on one document ?
Note: Notes Addin Menus have always had some problems identifying multiple document selections if you are working in a view through a frameset. In short; frameset-solutions may have problems with Notes Addin Menus!