When a customer orders a product sample, the product is clearly labelled as a sample in the cart and checkout. By default, "- Sample" is added after the product name (e.g. "White Wall Tile - Sample"). You can change the Sample label to anything you like.
The same label will be displayed after the product name in the order notification emails to customers and the store owner, and on order-related pages in the WordPress admin. This ensures that it is always clear that the customer has ordered a sample and not the full product.