Donald Trump has jabbed Jeb Bush for being "low-energy." He scoffed at Scott Walker for appearing "slow." He proclaimed Marco Rubio has "the worst voting record there is today."

But when his now-familiar scorn shifted to the other businessperson in the fight for the GOP nomination, he focused on her appearance.

“Look at that face!” Trump said, according to a Rolling Stone interview. “Would anyone vote for that? Can you imagine that, the face of our next president?”

After CNN debate moderator Jake Tapper pressed Fiorina for a response to the comments Wednesday, she coolly replied, “I think women all over this country heard very clearly what Mr. Trump said.”

The audience cheered. “I think she’s got a beautiful face,” Trump countered in a softer tone, one he hadn’t used to address the nine other challengers, “and I think she’s a beautiful woman.”

The line didn’t feel like a compliment.

Here are Donald Trump's most memorable moments from the second GOP debate. (CNN)

Fiorina, the former chief executive of Hewlett-Packard, also happens to be the only female Republican aiming for the White House. She shared the primetime stage with ten men, offering her foreign policy prescriptions and calling for tougher military action. She was the only candidate to be called “beautiful.”

Michael Kimmel, founder of Stony Brook University’s Center for the Study of Men and Masculinities, said Trump’s misguided praise sends a message: Fiorina’s thoughts are secondary to her body. The beauty of men in power, on that stage and generally, is rarely assessed.

“One moment [Trump] denigrates women by their appearances - not even taking them seriously as actual people with ideas - and the next minute he talks about how beautiful they are -- and again not taking them seriously as actual people with ideas,” Kimmel said. “Either way, they're objects for him to either admire or denigrate. Either way, it's patronizing and, frankly, embarrassing.”

Jackson Katz, author of “Leading Men: Presidential Campaigns and the Politics of Manhood,” said some men just don’t see why remarks on sex appeal can exasperate women.

“People who don't have the experience of being judged first and foremost on their appearance, who aren't assessed this way 24-7, don’t understand why that’s so frustrating,” Katz said. “The fact that [Trump] hasn’t been booed off the stage for these kind of comments shows you how far we still have to come as a society.”

The flattery seems more backhanded in the broader context of national data: Though half the workforce is female, only 5 percent of chief executives at Fortune 500 companies are women.

Decades of research shows unconscious bias can block women from corner offices -- meaning: If a hiring manager has worked around mostly men, or if they grew up with the understanding that business is inherently masculine, they’re far more likely to hire a man.

On the inverse, people who’ve bought into traditional gender roles are more likely to think that women should be kind, nurturing, aesthetically pleasing, more interested in child-rearing than the stock market. Not exactly the qualities one expects from a chief executive.

Which is why the qualifier “beautiful” in a professional setting can feel dismissive.

“What was disrespectful was interjecting her appearance into a discussion that should be about qualifications,” said Katie Packer Gage, co-founder of Burning Glass, a political consulting firm.

“By saying she was beautiful, [Trump] showed that he doesn't get it.”

Last week, another example of nice-sentiment-wrong-time went viral.

Charlotte Proudman, a British family lawyer, tweeted a message she received on LinkedIn from a fellow London attorney: “I appreciate that this is probably horrendously politically incorrect but that is a stunning picture.”

Some lauded her decision to share the note as honest and brave. Some wondered why she’d try to embarrass a man who complimented her. Some called her a “feminazi.”

Proudman’s explanation attracted global attention.

“I am on LinkedIn for businesses purposes, not to be approached about my physical appearance or to be objectified by sexist men,” she wrote. “The eroticisation of women’s physical appearance is a way of exercising power over women. It silences women’s professional attributes as their physical appearance becomes the subject.”