UXi has five different types of published content:

Media (used when an uploaded content image is set to link to attachment page.)
Locations (if the UXi Location add-on is active)

    The Layout Application tool is used to update the layout used by ALL instances of a specific type of published content (post, page, media, location, or testimonial)

    In the example above, all posts are being re-set to use a layout called 'Custom Blog Page'

    Bulk-Apply New Layouts
    1. Selecting an existing layout form the select box next to the content type to select which layout will be used.
    2. Check 'Update' to confirm your selection
    3. Click Apply Layouts to apply the change.