"Even if you agree that the picture is crass (etc) due to being from Playboy, a much more likely and respectful explanation is that the asker simply did not know the history of it."
There may be others. It is incredibly hard to sidestep the wider cultural framing that women exist solely as sex objects, they are prey and men are predators. It is a problem space I have thought long and hard about. I think my statement that your statement implicitly agrees with certain things is accurate.
However, it wasn't intended to accuse you, personally, of anything. The degree to which it does so is an error on my part. It is late. I am tired. Etc.
I wholly agree with you that jumping to accusations was poor form. I did not witness that particular discussion of the Lena test photo, but I have seen such discussions before on HN. They tend to be incredibly uncharitable. This is really common when anything vaguely related to sex enters discussion.
I do my best to respectfully critique it. I am aware sex is a very sensitive subject. But the subtext of most such derails is that all heterosexual sex is inherently abusive of women. I really think that needs all the gentle, kind push back humanity can muster. I do what little I can.
Best.