You can save a single image on product records or line item records. While file attachments can be any file type, the item image must be a .JPG, .PNG, or .BMP file. File attachments can be attached to emails but they won't print within the actual document, while the item image can print directly within the line item section of a document.
The image below shows the Xebra Line Item window with product 'LGB943 - Logo Golf Balls' loaded. The Image checkbox was checked which opened the Image window. The golf ball image was loaded into the image window. The image is stored with the line item.
The picture below shows the line item image on a quote document in the Xebra Print Preview window.