I think it's fair to say that conceiving of a prompt and iterating it toward a desirable output can be artistically expressive. Where the comparison with cameras falls down for me is a) at least to date, writing prompts feels a lot less intentional and a lot more random (AI people themselves make heavy use of the term "cargo culting") than [arranging and] composing a photograph, and b) your camera can function from first principles without requiring the work of other photographers to be blended into an information slurry and loaded into its memory.