What does the "two-man" folder icon mean?

My folder icon usually looks like this:

However, I have a folder (in the location %appdata% \ Microsoft \ Windows \ Start Menu \ Programs) that looks like this:

What does that icon mean?

What is causing this folder to have a special icon?

It would help if you'd specified which OS you're running (Windows 7, 8, 8.1, etc.)... but... I believe this means that the indicated folder will appear in all users' start menus.

I see this on my machine (Windows 8.1), not for that folder, but for %appdata%\Microsoft\Windows - meaning that the Start Menu and everything else under %appdata%\Microsoft\Windows form system-wide additions to the corresponding per-user directories.

(Edited - added:) To the OP: Please open a command prompt and type net share - if the folder shows up in the resulting list, it's a network share. If it doesn't, it's as described above, something Windows is doing to tell you "this folder is visible in all users' start menus". However, I have to say that I can't reproduce this on a Vista test machine. That is, the folder in question IS the system-wide Start Menu, but it doesn't appear with the "two-man" icon.

It is a shared folder. More info here