"There’s nothing to be embarrassed about," Donald Trump spokesman Jason Miller told CNN when asked about his boss's reaction to the New York Post's publication of nude photos of his wife, Melania. "She's a beautiful woman."

Miller is right that Melania is considered beautiful. But the photos published by the tabloid are not about beauty. Nor are they playful snapshots by an ex-boyfriend (or girlfriend) or, as Miller suggested, a "celebration of the human body as art." They are erotically charged images intended to arouse or titillate and appeal to what the Supreme Court called "prurient interest" in its 1973 definition of pornography. The photos sell not art or beauty, but sex. (They were originally taken for a now-defunct French men's magazine.)

While the images have gone viral on social media, the mainstream media, apparently embarrassed or accustomed to conflating celebrity with shamelessness, have been silent.

Consider Kim Kardashian, the privileged daughter of O. J. Simpson's late defense attorney. When a 2003 sex tape featuring her was leaked in 2007, she refused to be embarrassed or "slut-shamed." Instead, she sued the company that distributed the video and used her reported $5 million settlement to launch her wildly successful reality TV show. As of 2016, her family's net worth was estimated at over $300 million. When the mother-of-two recently posted a nude selfie on Instagram, she asserted that displaying her body "empowered" her. And, of course, her husband Kanye West, the rapper and entrepreneur, has announced that—wait for it—he intends to run for president in 2020.

Sharing nude selfies is just the latest form of "empowerment," or exhibitionism, at the expense of self-respect. Prosecutors across the country have been confounded about whether to criminally charge minors who "sext" indecent photos to one another. One scandal last year involved more than 100 students at a high school in southern Colorado—about 10 percent of the student body. Maybe that explains the silence over Mrs. Trump's indiscretion: We've become inured to such self-inflicted violations of privacy.

Not long ago, being president demanded a measure of decorum. But that was when Americans expected more from their politicians (and from their celebrities). Yes, Ronald Reagan and Nancy Reagan were actors. But they conducted themselves, on screen and off, in ways that made their transition to the Oval Office relatively seamless. Can you imagine a young Nancy Reagan posing nude? Or a youthful Betty Ford, then a model and ballet dancer? Or, for that matter, former first lady Hillary Clinton?

At the same age that Melania was primping for those photographs, Hil­lary Rodham was finishing Yale Law School. Michelle Robinson Obama had just graduated from Harvard Law. Laura Welch Bush was teaching elementary school in Houston and preparing to get a master's degree in library science at the University of Texas. Many attractive women have more on their minds than their bodies.

Are we holding women to a higher standard than men? No. Anthony Weiner, a gifted politician, was savaged for sending inappropriate images to female admirers. And he never sold them or intended them to become public.

For those who see the photos as mere youthful indiscretion, Melania posed for equally tasteless images—handcuffed to her then-boyfriend Donald's briefcase on his private jet—when she was 31.

Mr. Trump defended those photos too. Small wonder. Everything and everyone is for sale in his transactional universe.

Judith Miller is an award-winning writer and author and an adjunct fellow at the Manhattan Institute. Ann Marlowe, a writer in New York, is a visiting fellow at the Hudson Institute.