Another new launch Gmail Labs features where you may preview your messages while waiting for the Gmail to be completely load. The new features is named as
If you are on the high speed internet connection, then this features may not benefit you. But try to imaging that you are on the very slow internet connect which may take several minutes to only completely load your inbox. How bore you are while you waiting for that and you find nothing to do besides look at the loading bar and counting the movement of the bar.
In addition, if you only found out that there is no any new message for you to read after servaral minutes of waiting, how disappointed you are.
Gmail always try the best to make their product become more user friendly you may have a static preview of your inbox with the 10 most recent messages on the screen.
What you need to do is just to turn the Inbox Preview features on in from the Lab tab under the settings.