If you are seeing duplicate images on your home page, or in the content archives, this means that you have set both:
- your featured posts widget or
- content archive settings to show the full post content
which tells the theme to include the image at the top of the post, as well as to include the featured image.
To remedy this you'll either want to choose to show an excerpt or no content and include the featured image, or show the content but do not include the featured image.
Note: as of 2019, we no longer recommend displaying an excerpt or content in "Featured Posts" widgets, or Archives settings. Readers should be able to tell what the recipe is based solely on the image + title.
If the problem is on your home page you'll want to make the above change in the Foodie Pro, Cook'd Pro, Brunch Pro, Seasoned Pro, or Cravings Pro Featured Posts widgets in the Homepage: Top, Homepage: Middle, or Homepage: Bottom widget areas.
If the problem is showing up on your content archive pages (categories, tags, search) then you'll want to adjust this in the content archive settings (Appearance > Customize > Theme Settings > Content Archives).