Images are suitable for backgrounds or as stand-alone statements.
They look great on blog post headers, Facebook instant article images or in an Apple News long-form story.
Larger sized images definitely lend themselves to printing/publishing projects like books or eBooks.
They look great when you want to flood the whole (computer) window with colour like below.
See image #26 in the Aurasoma series and notice it uses the colour orange only. This works well if trying to integrate an image into an existing story colour scheme. This is a 3000px version.
Application of these images is boundless. Tell a story with a slider.
Place a text overlay and capture audience attention. Intersperse colour judiciously into a text-heavy dialogue.