Thus, in order for this template to be permissible, the image itself must also be free under copyright law - whether because it's in the public domain (e.g. covered by a tag such as {{PD-USGov}}, or {{PD-old}}) or because it was freely licensed by the photographer or copyright holder; see Commons:Copyright_tags.

In a nutshell:

There are special provisions in copyright law to exempt utility articles to a wide degree from copyright protection.

See this derivative works exception. In brief, per the Supreme Court’s decision in Mazer v. Stein, useful articles, regardless of factors such as mass production, commercial exploitation, and industrial designs are not subject to copyright protection. The declaration that “pictorial, graphic, and sculptural works” include “works of artistic craftsmanship insofar as their form but not their mechanical or utilitarian aspects are concerned” is classic language; it is drawn from Copyright Office regulations promulgated in the 1940’s and expressly endorsed by the Supreme Court in the Mazer case. The design of a useful article shall be considered a pictorial, graphic, or sculptural work only if, and only to the extent that, such design incorporates pictorial, graphic, or sculptural features that can be identified separately from, and are capable of existing independently of, the utilitarian aspects of the article.” A “useful article” is defined as “an article having an intrinsic utilitarian function that is not merely to portray the appearance of the article or to convey information.”

A two-dimensional painting, drawing, or graphic work is still capable of being identified as such when it is printed on or applied to utilitarian articles such as textile fabrics, wallpaper, containers, and the like. The same is true when a statue or carving is used to embellish an industrial product or, as in the Mazer case, is incorporated into a product without losing its ability to exist independently as a work of art. Although the shape of an industrial product may be aesthetically satisfying and valuable, that does not entitle it to copyright protection. Unless the shape of an automobile, airplane, ladies’ dress, food processor, television set, or any other industrial product contains some element that, physically or conceptually, can be identified as separable from the utilitarian aspects of that article, the design cannot not be copyrighted. The test of separability and independence from “the utilitarian aspects of the article” does not depend upon the nature of the design—that is, even if the appearance of an article is determined by aesthetic (as opposed to functional) considerations, only elements, if any, which can be identified separately from the useful article as such are copyrightable. And, even if the three-dimensional design contains some such element (for example, a carving on the back of a chair or a floral relief design on silver flatware), copyright protection would extend only to that element, and would not cover the over-all configuration of the utilitarian article as such. Subject to disclaimers.