Few first ladies have been more prepared for their close-ups than Melania Trump.

Yet the former model has not graced the cover of Vogue, Glamour or Cosmopolitan during her husband’s first 20 months in office. Neither has she yukked it up with Stephen Colbert, Jimmy Kimmel or other late-night TV hosts.

That’s a huge missed opportunity for the Trump White House, says Lauren A. Wright, lecturer in politics and Public Affairs at Princeton University.

Others insist Mrs. Trump’s low pop culture profile smacks of media bias that extends to other women in the Republican administration.

“[Mrs. Trump] has this toolkit that makes her a unique, powerful surrogate. … It’s so rare for a White House not to take advantage of that,” Ms. Wright said.

The modern first lady routinely graces the media landscape in creative ways. Michelle Obama, for example, appeared on the popular “Carpool Karaoke” segment on CBS’s “The Late Late Show” with host James Corden. The Atlantic noted Mrs. Obama’s appearance and described her banter with Mr. Corden as “lively and watchable, but definitely driven by an agenda.”

Mrs. Obama appeared on the covers of Vogue (three times), Time, Glamour, Essence, InStyle, Redbook, Cooking Light and O, The Oprah Magazine, among others, during her eight years in the White House.

Mrs. Trump appeared on the covers of British GQ and Vogue before her move to 1600 Pennsylvania Ave. NW.

Even Nancy Reagan flexed her pop culture might when she appeared on NBC’s “Diff’rent Strokes” in 1983 to promote her “Just Say No” anti-drug campaign.

Such appearances offer “a really good opportunity to get that different audience without being called unpresidential,” Ms. Wright said.

Villanova University communication professor Susan Mackey-Kallis noted that Mrs. Trump has given fewer speeches than either Mrs. Obama or Laura Bush, at least up until this point in the Trump presidency.

“She seems far more uncomfortable taking a place on the public stage than did her predecessors,” Ms. Mackey-Kallis said.

Media interest in the first lady’s whereabouts remains sky-high, she said. Witness the imbroglio surrounding Mrs. Trump’s extended public absence this year after kidney surgery.

Ms. Wright agreed, saying talk-show bookers would love to have this enigmatic first lady on their shows.

“Media organizations want eyeballs,” she said, and Mrs. Trump’s absence likely comes down to the first lady’s decision.

Four late-night TV shows contacted by The Washington Times did not comment on whether Mrs. Trump would be on their shows soon or whether they were open to an appearance by the first lady.

Mrs. Trump may simply prefer to avoid the spotlight as much as possible at this stage in her life, Ms. Wright said, even while she keeps up with the latest headlines.

“When she sees something she doesn’t like, she speaks out,” said Ms. Wright, noting that Mrs. Trump weighed in on the need to find bipartisan solutions for U.S. immigration policies.

Julie Gunlock, director of the Center for Progress and Innovation at the Independent Women’s Forum, said Mrs. Trump’s pop culture blackout smacks of the media’s anti-Trump posture.

“There’s absolutely no defense of this,” said Ms. Gunlock. “It’s snobbery, mean-girl behavior, whereby featuring her they would be humanizing the president. You can’t like Melania. In liking Melania, you’ve at least approved of one of his decisions.”

Ms. Gunlock said a similar tactic is underway with some of President Trump’s most powerful female appointees.

“Why hasn’t [U.N. Ambassador] Nikki Haley been featured … in these puff pieces, a regular offering on the newsstands?” she said.

Obama administration officials such as Samantha Power (Vanity Fair) and Susan E. Rice (Vogue) have made the magazine cut.

Then again, Mrs. Trump may not want to grace stage of CBS’s “The Late Show” minutes after host Mr. Colbert savages her husband’s policies. That may be partially the reason behind her lower profile, Ms. Gunlock said.

“Who would want to expose herself to that kind of cruelty?” she said, noting that the hosts of ABC’s morning talk show “The View” mocked the first lady’s accent and actor Peter Fonda tweeted his wish that her 12-year-old son, Barron Trump, be caged with pedophiles. (Mr. Fonda later apologized.)

Mr. Trump upended plenty of presidential norms during his first months in office. Larry Chiagouris, professor of marketing at Pace University, suggests the media are similarly throwing out some unwritten rules when it comes to first ladies.

Modern news outlets often take sides, a departure from journalistic norms, “in the interest of Nielsen ratings and subscribers,” Mr. Chiagouris said. “Rules such as treating the family members of politicians with respect are among the casualties.”