The Content Feed is different than the other feed types; you cannot change the layout. The content feed may be, for example, a folder with multiple files. Each file will play in the content feed. You can change the items within the content feed without re-deploying to the player.
Create a Content Feed
Navigate to the content library and select your folder. Right click and select New Content in this Category '[folder name]' >> Content Feed....
The Properties window will open. Give the content a descriptive Name.
Determine the Recurrence of the content.
Click the Ellipsis button to find the file path/URL for the content feed.
Click on the Ellipsis or use the drop-down list to enter the Data format.
Ensure that the Deployment Behavior is correct.
If you want to filter or sort your content feed items, click Filter and Sort.
The Layout Properties window will open. Select your data field and filter/sort from the tabs to the right side.
Click OK and Save.