You can upload your own images to products that you've added to your Products List, or choose product images that your Market Manager has already uploaded and made available to you.
Using Existing Global Product Images
Most likely, your Market Manager has already uploaded some global product images which you can use for your products. To access these images, click the "Select Image" link in the image field of the Product and select an image from the relevant folder.
Uploading Your Own Product Images
You can also upload your own product images, by clicking "Upload Image To This Folder" and then selecting it as the image you'd like to put in place for a particular product.