Facebook today introduced a total new look to Facebook messages. This new look is totally different from the old one and is a side by side Layout. In this new format you will be able to see your recent messages from your friends on the left side and your complete conversation with the selected friend on the right side.
The another advantage of this new look of Facebook messages is that you can also view different photos and emotions which you have sent your friends in a complete different way . This can be considered as bringing your Facebook chat to Life.
Facebook has also Improved its Search and Navigation that is you can search by a sender’s name or keyword from the main messages view. You can even use keyboard commands for easier navigation on Facebook messages. If you are looking for a list of available shortcuts, type Alt Q on a PC or Control Q on a Mac.
This changes was started by Facebook under the name “mercury project” . A team was selected for this purpose and was working from a long time on this project . Here is the complete details about the Official Facebook announcement regarding new Look for Facebook messages :- https://www.facebook.com/notes/facebook-engineering/under-the-hood-improving-messages/10151032941658920