Absolutely not. While the camera may capture a sadness in a smiling person's eyes, it also may not. A photograph has no power to explain itself. Even a photograph of a grieving person may not tell the real story of that person's grief, though it may very well touch the heartstrings of viewers.
Anyone can take any photo and give it an explanation that may or may not have even an element of truth in it. Check out the following link: http://idealbite.com/100-percent-of-what-you-see-i...
and even selfless are now no exception:
Portraying images as they are not has become a passion and reflects the unrealistic expectations of today's culture. The resins behind the whole business explains much of the dissatisfaction people have in life. However, boocoodles of money has been made by opportunists promoting someone else's idea of perfectness.
On another note, a photo can allow someone to tell a story that is not true. Think of natural disasters. The pictures portray devastating loss with survivors in need, but what are the realities? Cities opened their doors to the needy, but the stories of how too many of those needy people destroyed property, preyed even on each other, and committed crimes were a blip on the news media's radar, if that.
No, photographs, like all things, should be proven.