The development team Gmail not to. After we introduce the markers Nested (learn how to use them), the team has implemented in Gmail Labs more a way to make use of the service e-mail efficient on another level. I speak of the quick view messages, which saves open the message page to know what a sender sent.
To enable the tool, go to Settings > Labs and check the box Enable next message Quickview. Then save your changes at the bottom.
The description of the resource already explains how it works: “to look into a conversation without opening it, then right-click the message in your Inbox.” That is, click the right mouse button allows you to quickly view the message content.
When the right button is pressed on a message quickly a box pop-up is loaded with the subject of that message and the sender. If several are grouped MESSAGES in a conversation, e-mail user will be able to browse through them using the arrows to the left and right in the housing bottom (or top depending on where it was opened). There are still options to archive, delete and mark as read (usually new messages displayed thus remain as unread).
Verdict: is another “Lab” that it pays to be triggered as soon as possible. It saves waiting time while messages of pages are loaded. It also ensures a quick reference to certain emails. Just one thing that the display does not do (and, if allowed, would defeat the very purpose of existence): scroll the message. Has bar rolling.