msycamore said:

Oh... so that is what it was! Now when you say it, I think it resembles the footage in the doc: Magic & the mystery pretty much although that is more saturated. How did you find out?

It's in the SE section of the LFL photo catalog which has all SW pics for promotion.

And usually if there is a straight screenshot in a commercial release, it's not from the original films. I don't remember seeing any screenshots that promote something or are found in books etc., they're all promotional images taken with a camera. There are over 200 screenshot images for promotion from every SE film and now you also have the 2004 in HD where you can get any shot you want so I don't think you are going to find an original screenshot from an official release.