The Thumbnail photos are not clear the first time you visit the site, but it will be clear after you visited the product detail page and then come back.
i have attached a photo, you can tell the first 2 Thumbnail are clear because I have visited the product detail page but other photo are not clear.
I saw the screenshot you attached and tried to visit your website but was unable to visit. Please make sure that your website is working to check it myself and help you out accordingly.