The central idea of the poem "A Photograph" is to highlight the power of a photograph in capturing a moment in time and preserving memories. The poet reminisces about an old photograph of his mother, which evokes strong emotions and memories.

Memories Captured in a Photograph
The photograph captures a specific moment in the past, freezing it in time. It becomes a powerful tool to evoke memories and emotions associated with that moment. The poet describes how the photograph of his mother brings back memories of her youth, her long hair, and the unique smell of her saree.

The Passage of Time
The photograph also serves as a reminder of the passage of time. The poet realizes that the person in the photograph is no longer the same as the person he remembers. Time has changed her, and the photograph serves as a connection to the past.

Emotions and Nostalgia
The poem is filled with emotions and nostalgia as the poet reflects on the photograph and the memories associated with it. The photograph becomes a conduit for the poet to connect with his past and relive memories that have long been forgotten.

Conclusion
In conclusion, the poem "A Photograph" is a beautiful reflection on the power of photographs to capture memories and evoke emotions. It is a reminder that photographs are not just images on paper but hold significant meaning and importance in our lives.