Thank you, LarissaAnn, for posting the photo I had earlier described.

The first time I saw that photo, its significance went right over my head. However, a couple of summers ago while visiting the Romanov exhibit in Santa Fe, my friend and I noticed a blow-up of the photo, then added two + two with regards to the information about Voronov and Olga sent to me by another friend in Yalta. Later I was delighted to find the museum catalog featured an article on the very subject.
Initially, Margarita, I also had thought the photo might be slightly damaged, but on closer inspection saw that all four faces were exposed to a great deal of sunlight, Marie's and Tatiana's in particular. So what I think we're seeing is Olga looking both shy but pleased, Marie squinting against the sun, Tatiana holding a very deep wink for benefit of the photographer (Anastasia?), and Voronov--being the professional that he was--gamely smiling for the camera, but definitely finding himself in a rather tricky situation!
