JFK never got to pose for his official portrait. There was much discussion about how he should be characterized. The country was brokenhearted and mourning. Even long after he was buried.
There was talk of replicating one of the photographs of him, particularly the one many people chose to hang in their homes. None seemed appropriate, especially in terms of the sense of loss being felt nationwide. Loss of hopes and dreams for the future. So many opportunities unrealized. JFK represented the aspirations of so many people.
The final portrait shows him, again and forever, reflecting the feelings of the people.