I recently gave a test lecture about a topic in statistics, where I showed a meme that a statistics professor I follow shared on her Twitter feed [1]. I thought it would be safe to include as it didn't get any negative reactions on Twitter and was already being used by a professor in her university class in the US. After the talk I immediately got called out by the women's representative on the hiring commission, who…
If you've been strongly sensitized to feelings of actual or potential distress due to unwanted sexual attraction, or the sexualization of the (in this case) female body, or whatever the problem might have been, it's probably seen as wrong or at least problematic. The sensitization might have happened due to personal experiences, or due to hearing a lot about such experiences from other people, or, well... *looks around on the Internet*.
If you haven't been strongly sensitized that way, there probably isn't anything particularly wrong with that. Most people would probably have some kind of a middle ground perspective where e.g. physical attraction, and its expression (and humour about it) is part of normal human experience. The same people might see it as lewd or inappropriate in other contexts, or if expressed in other ways, or when it's too much. It might sometimes feel uncomfortable, and the extent to which people tolerate (and want to tolerate) that varies, as does the line where people begin to deem it "not right".
Which part of the spectrum is right or wrong is not an objective question. Right now lots of people (at least in social media) seem to be rather preoccupied with the former, perhaps because legitimate problems have often been overlooked. Some people who are in the former end of the spectrum are being rather aggressive. The anger is often understandable, although that doesn't mean they're objectively right or that you're wrong if you don't follow the same line.
With that said, people who were already sensitive about not causing ill feelings were probably not the actual problem in the first place.
This is just my random view, of course.