A gray image with the word "Stores" is a placeholder image and is appearing on your deal erroneously. 

If your deal is low-touch (not featured), confirm that there are no spinning circles (broken image links) and delete any that are present.

If your deal is featured and you see this image in place of an image on your deal, submit a Helpdesk Ticket, as an image is missing and will need to be added by the Groupon team.