“Title” would be a more appropriate word. Titles break down barriers for the viewer, but should not limit that experience. Typically a title naming the objects in a photograph says that is all the photograph is about. The viewer is directed not to see anything more than that. The use of “untitled” gets in the way of a viewer’s experience of the work, they may wonder where the photograph was made stopping them from getting further involved. Usually, by titling with a place name, like “Hernandez, New Mexico,” a barrier is removed.
Titles reveal the intentions of the photographer. Had Walker Evans entitled his photograph of a church in Alabama, “Church in Nonesuch, Alabama,” vs. the actual title, “Alabama,” the later implies the photograph is more about a whole culture, not just the thing itself, and expands the viewers experience.
The worst titles are the cutsie ones, like sunset. They direct the viewers experience rather than giving them credit they could see something more in the photograph that is more than an obvious subject or object, even seeing something more than the artist intended.
All photographs that are works of art are about something more than what they are of. For the viewer, the art of seeing, or receiving, is a participation in the creative process no less essential and direct than the artist’s. Do not limit the experience with poorly chosen titles.