A merely ornamental refusal is issued by the USPTO when the applied-for mark is considered to serve purely a decorative or aesthetic function rather than identifying the commercial source of the goods. The mark does not function as a trademark because consumers would perceive it as ornamentation, not as a brand identifier.
This kind of refusal is common with large, prominent graphic designs or phrases placed on clothing or accessories where the design dominates the product visually. A large decorative graphic across the front of a T-shirt is typically viewed by consumers as a design element, not as a brand identifier. The same graphic used as a small, distinct logo on a collar tag would likely be viewed differently.
Overcoming a merely ornamental refusal typically requires showing the mark is used in a manner that consumers would recognize as a source identifier: smaller, positioned consistently with brand marks, or accompanied by evidence that consumers associate it with a specific brand.