Perhaps QV felt this way: Intimacy with one's partner . . . no prob! But, with regards to anything the servants must take care of . . . keep it discreet!
And from what I've read about Alexandra, I think she was of a similar mindset. She and Nicholas are usually so restrained in their photos,* but we know that Nicholas and Alexandra were very passionate in private.
And with regards to that famous "bare bottom" photo . . . I've always wondered if "the imp" didn't happen to take that photo. It was found in the OTMA scrapbooks, after all, and I think Anastasia--far more than any of her older sisters--would have been just the one to have been siddling around the Standart, waiting for her opportunity!
* The one exception being that very funny photo of the two of them kissing, with Xenia and Sandro kissing nearby, and Olga A. standing between them with a goofy expression on her face!