The design details page (or single design view), displays all information including revisions of a designs.
Navigation
At the top of the page, you can either edit the item you are currently viewing, or add a new revision to the design that you are looking at. Additionally, you can approve or decline the item that you are viewing.
Below the navigation you can see the title of the design and the title of the item you are currently looking at, indicating whether you are looking at the original design, or a revision.
Next to the title you can toggle the display of the item details, by clicking the "Details" button. The details include the description and the list of people who approved or declined the item.
Full View Zooming
Below the title you can see the full view of the item. You can click on the image to zoom the view to 100%, and then move your cursor into any direction to navigate on the image. Click again to exit the zoom mode.
Revision Manager
Below the full image and the recent revisions, you can see and manage all revisions belonging to the current design. By default, the items are hidden and you have to click on the "Show All" button first to make them visible.
Assuming you have the permission to edit revisions, you can tick the checkbox next to each item and then perform the desired action at the top of the list via the bulk-action button.