"What's new" text area behavior variation on static home page

Facts:

WP 3.5
BuddyPress 1.6.2
bbPress 2.2.3

Problem:

On my static homepage I have a “What’s new” text area for posting updates and it is accompanied by a “Post In” pop-up list of groups and a “Post Update” button – here.

However, on other pages in the site like for the activity feed page

the similar text area is just a plain box and the group pop-up list and Update Post buttons are hidden until the user clicks in the text area to actually make an update. This is much preferable since those graphic elements do not take up space on the page unless needed by the user.

I’d like to change the “What’s new” area on the homepage to match this behavior. Where would one go about customizing this behavior? How would one do so?