PenciDesign Supporter replied
Hi,
Unfortunately, you can't select the image display on the selector screen, because the JS code of Pinterest will scan all the image on your site and show it to the user.
You can use the jQuery Pin It Button for Images plugin here to show the pin button for each image on your post: https://wordpress.org/plugins/jquery-pin-it-button-for-images/
Regards,
PenciDesign.