Card layout for images with cover treatment

Hi. Any reason why this will not render the cover treatment for images?

photos: 
  label: Photos
  type: files 
  query: page.images
  empty: "No photo yet"
  layout: cards  
  image:
    cover: true

Wait a minute. It’s been some time and I returned to the panel, refreshed the page and the images now render with the cover treatment. I suppose this was a cache/temporary issue that magically fixed itself.