Primarily, we designed the Beta to offer greater opportunities to customize your Group (click customize in the upper-right of the home page to see how) and to integrate the diversity of your Group’s content into one place: the new conversations area.
So, files, photos, and links aren’t located in different areas within Groups anymore. Instead, they’re all combined with messages in conversations the chain of messages posted within a topic (you know, where Cathy replies to Hank, Yvette replies to Cathy, etc.). For anything you want to add to the group—whether it’s a message, some photos, or a file—you take the same action: you create a post (by clicking conversations, then start new post).