1. In a digital media environment to facilitate creation of content using one or more computing devices, a method comprising: outputting, via a user interface for a digital media application, an image panel displaying image search results having candidate images for insertion in an image frame placed in a document exposed for editing via an editing panel of the user interface, wherein the image search results contain images matching at least one of image frame size or image frame shape; detecting input to select a particular image within an arrangement of candidate images displayed in the image panel; responsive to detection of the input, generating a preview image of the document having the particular image inserted into the image frame; and displaying the preview image in the user interface as a preview that replaces a view of the document exposed for editing in the editing panel as long as the input to select the particular image is maintained.