Currently, the store thumbnails are based on the target website's screenshot and not on individual coupon. You can manually change the thumbnails though. Thanks.
I want it to display the 1st image of the every post as the thumbnail featured image. So different post will have different thumbnail image (getting the 1st image of the post). Let me know if this is possible. I will be glad to grab a copy of clipper theme if this is possible.
It's not a default function of the theme to work the way you describe, so it would require customization on your part if you were looking to set it up this way. Our themes are not encrypted, so you are free to modify them as you wish. Thanks.