The photo you reference was a "Posed" Photograph. You do know that, right?
Not only do I not know that, but Jefferson Morley doesn't know that (this is from his JFK Facts Substack):
"Later in the afternoon of November 22, Johnny Flynn, a photographer for the Dallas Morning News, captured two Dallas plainclothes detectives looking at the park bench where the couple sat and examining the bag lunch they left behind. The photo confirms the details in Sitzman’s account, and begs the question: what happened to the couple on the knoll?"
Was the bench posed as well? The lunch remains (Tom Thumb buns?) posed? The detectives posed? Johnny Flynn posed? All to confirm Sitzman's story - or was she part of the conspiracy too? Golly, just the effort to cover-up the Black guy with a rifle and tripod was a pretty elaborate conspiracy all by itself!
Believe what you wish, but these ad hoc explanations do end up looking like a Rube Goldberg contraption - all to prop up a photo that has been examined umpteen times. If you can actually prove something new and different, go for it. I say pareidolia until you do.