If you don't install this extension ("Norton Security Toolbar" ) for IE or Google Chrome for instance, you will not see any Safe Web icons during the Google searching results.
Description about the extension: > Norton Safe Search and Safe Web warn you of dangerous sites when you search, shop or browse online.
But if you go to Norton -> Settings -> Identity protection -> "Safe Web" it is not grayed out. It should be grayed out. If you don't have the extension installed. Now It is pointless to set Safe Web On/Off, it does not work. Best example are the icons of course.
My opinion:
No Extension installed: Safe Web should be grayed out, and create a link to add the extension to turn on Safe Web, so it does work.