When I click with the right mouse button on the Messages icon on the dock bar, I see there is a "Show Recents" menu item.
When I click on it, the only thing it seems to do is showing me a Finder window. It hides the other windows, and when I click on the desktop, the window I was seeing before re-appears. In my case, I had Safari open, and its window was hidden until I didn't click on the desktop.
What is that menu item supposed to do? Is it working correctly?
Update: It doesn't seem that menu is specific for the Messages application. Dock icons for applications that are not running show that menu item. I don't see it for Mission Control, Launchpad, Downloads and Trashcan. I see that menu item for System Preferences, and Reminders, for example.
Best Answer
The official documentation is very thin for messages (it doesn't even have an entry in the Applications section of OS X support online)
It could be working correctly if it's just a stub to allow you to see some recent messages when the application is not running, but that functionality isn't present today. Once you start up the app, the Show Recents menu item in the dock is suppressed and you instead get to show the various windows that the app could have open.
So - it's useless and could get hidden if it's simply a bug or perhaps an update will add this functionality so that it actually shows something that has happened recently since it doesn't show any recent activity at 10.8 build 12A269.