Using the OK button:
If you have highlighted an image frame in the Design Essentials window, and you have selected an image in the Images window, pressing Apply or OK results in the new image replacing the current image on your design page.

Tip: A faster way to apply a selected image is to highlight an image frame in the Design Essentials window, then double-click the preferred thumbnail in the Images window.

Dragging and Dropping:
You can drag and drop images into an image frame from Explorer or some third-party image browsers, as well as from the Design Essentials Images window.

From the scrapbook:
If you have stored an image in the scrapbook, you can drag and drop it into an image frame.

From another image frame:
You can replace an image in a frame by dragging and dropping an image from another frame.

Tip: If you want to use the current image elsewhere in your document, place it in the scrapbook before adding the new image. This allows you to place the new image in an empty frame.