Custom image on shop / blog archive
The theme comes with a feature that allows users to add specific images for Shop and Blog archive, different from single pages feature images.
In this case, you can select two images, one that will be displayed on the archive page and the other one for the single page.
To add a specific image to your shop archive you will need to go to your single product page > edit page > product options > product archive image
If you want to add a specific image to your blog archive you will need to go to your single post page > edit page > Post options > Post archive image