You can call it a mental image if you are awake, or a dream if you are asleep. If you get this kind of vivid picture while you are in the process of waking or falling asleep, you might call it a hypnopompic or hypnagogic hallucination. Otherwise, it could be called an hallucination if it is connected with some pathological or drug related cause.
When I went to a wedding ,I pictured the beautiful dress of the bride in my mind.
I have always pictured us together. In a jail cell at least.He pictured the image in his mind as it was described to him.
Pictured on something.
Imagination
reconstruction
Nikola Tesla pictured it in his mind and later he came up with the patent.
perseverance
Not Pictured
reconstruction-APEX
Hyperbole
A possibility that comes to mind is something called narcissism.
There Is Something on Your Mind was created in 1978.