Love this rare behind-the-scenes shot of the crew having a laugh while rehearsing. (See bottom of this post for a color photo taken at the same time.)
Back in 1976, I was always on the hunt for ST-related items in any type of magazine. In Macon, GA where I lived (my hometown) there was a used bookstore downtown that I went to when I could. They had stacks of pre-read magazines of the tv/movie-fan sort, and they very often had ST articles and photos in them. A good part of my Star Trek scrapbook was from these sources, and one had a regular monthly ST photo as a feature, and that was always great to find. When it was a big article like this one, it was particularly exciting, especially when it talked about the possibility of Trek returning.
Not from the magazine, but found online, this awesome behind-the-scenes picture was taken during the same rehearsal as the one on the first page of the article. Nichelle is vamping it up here in a way I've never seen and I adore it. She seemed to be the life of the party that day! Here's a larger version, although darker.