President Donald Trump has long remarked on people’s physical appearance, but according to linguistics professor Deborah Tannen, the president has demonstrated a stark difference in the way he comments on the appearance of women when compared to men.

“There has always been a lot of talk about comments on women’s appearance, but it’s usually their clothing or how their hair looks,” Tannen said, speaking with The Washington Post in a report published Friday.

Trump’s remarks on the physical appearance of men often include reference to their height or size; he’s called former New York City Mayor Michael Bloomberg “Mini Mike,” Secretary of State Marco Rubio “Little Marco,” and North Korean Supreme Leader Kim Jong Un “Little Rocket Man,” among countless other attacks on men's height.

For women, however, attacks on their physical appearance frequently make reference to their attractiveness; “horseface,” he called adult film actress Stormy Daniels; “Miss Piggy,” he called former Miss Universe Alicia Machado; and “she’s no longer a 10,” he said of German-American model Heidi Klum.

When Trump praises men’s physical appearance, he also makes frequent reference to their height or size; “I have a friend, big guy, one of the biggest in the world,” Trump once said during a rally. He’s also made countless references to men as “big, strong guys” over the years.

For women, however, Trump’s praise also tends to focus on their attractiveness; “You don’t mind being called beautiful, right?” Trump asked Italian Prime Minister Giorgia Meloni last week while at a peace summit in Egypt; “a fantastically attractive person,” he said of Sen. Katie Britt (R-AL).

“These examples are different because it’s about the physical body,” Tannen said. “That is much more threatening and creepy and inappropriate.”

Others, like Allison Prasch, a professor of rhetoric, politics and culture at the University of Wisconsin at Madison, told the Post that Trump’s frequent remarks on people’s physical appearance were a tool to define both his perceived allies and enemies.

“Trump is not focused on a larger sense of identity,” Prasch said, speaking with the Post. “He is focused on one individual and his power to define them for good or for ill.”

In an email to the Post, the White House defended Trump’s tendency to remark on people’s physical appearance as proof of his authenticity.

“President Trump doesn’t care about being politically correct,” said White House spokesperson Liz Huston in an email to the Post. “The American people love how authentic, transparent, and effective the President is, which is why he won a massive landslide victory last November.”