Okay Alan,thanks. I can see the dark streak that is no doubt the vertical linear feature I sketched.
Thank
you, Mr Hackerott. I had written off the dark streak in this frame as an anomaly-----------------

------------------but your information from your recent viewing of Darnell at the Museum makes it clear that it's present in multiple frames (and against a white background).
The thought occurs that the relationship of hand(s?) to dark vertical line may not be accidental:
A Coke bottle? 