The scientific visualization of the brain as it processes the imagery and imagines the imagery is powerful - the two processes - viewing and imagining are virtually identical. Consider, then, the reality that what we take into our mind through watching visual media does indeed stay with us...and we access it through our imagination, thereby seeing it again whenever we wish to simply "call it up" from our stored memory. And, the mind doesn't differentiate between seeing and imagining. This is why we can view media and suspend our disbelief.
The implications for the mental processes of imagination are quite astounding...and relevant to a host of ideas, concerns, challenges and opportunities for artists creating visual media.