If you have images in your ecommerce store that you don't want on listings on Catch, you can block the image in CatchFeeder.
Login to CatchFeeder.
Find the product with the image you wish to block. Go to 'Products - All Products' in the left hand nav and search for the product. Click the product title in the left hand side of the table to go through to the product page where you will see the full data of that product.
Right click on the image at the top that you want to block and click 'Copy Image Address' or 'Copy Image URL' depending on your browser.
Go to 'Settings - Catch - General'. In the field 'Exclude these images' paste the URL. You can add multiple URL's here, add each URL on a new line. Click the 'Update Settings' button at the bottom of the page to save.
Go to the dashboard and click 'Upload to Catch' and wait for the sync to finish.