Seoul (CNN) It was the eve of President Donald Trump's historic steps into North Korea , and as the US delegation was lining up for a photo op with their South Korean counterparts at the Blue House, Secretary of State Mike Pompeo paced behind the group, looking for his opening.

Trump and President Moon Jae-in had taken their places in the center, followed by Moon's wife, Kim Jung-sook. The next US official in line was not a member of Trump's Cabinet or national security team, but his daughter and senior adviser Ivanka Trump.

As the cameras flashed and Pompeo awkwardly shuffled around, it took the first daughter a moment to realize he was trying to slide in. She eventually moved aside to let the secretary of state take his place between her and the South Korean first lady.

The moment encapsulated the unusually prominent role Ivanka Trump has played during Trump's trip to Asia: a first daughter assuming the spotlight and duty beyond that of a senior aide on the world stage, the latest in her ongoing efforts to style herself as a diplomat.

Back in Washington, national security officials bristled at the large presence Ivanka assumed while overseas. But those close to the President described it as business as usual.

In the spotlight

The administration -- the East Wing, in particular -- has made it clear that Ivanka Trump is not the first lady. But Melania Trump, who accompanied the President on recent trips to Europe and Tokyo, skipped the visit to Osaka for the G20 summit and following trip to Seoul. Her communications director and now White House press secretary, Stephanie Grisham , declined to provide a reason for the absence. In turn, the first daughter asserted herself abroad this week in unique and unprecedented fashion as both a member of the US delegation and a member of the President's family.

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Never before has a President's child had the proximity, influence and the marketing savvy to create a space in an administration, and that was on display from the G20 to the demilitarized zone as she appeared on equal footing with Cabinet-level officials. One sign of that: Her efforts to build relationships with world leaders at gatherings such as these.

Over the course of the four-day trip, Ivanka Trump attended multiple bilateral meetings at the G20 in Osaka. She was on stage for a women's economic empowerment forum with Japanese Prime Minister Shinzo Abe and Queen Maxima of the Netherlands, delivering remarks on her Women's Global Development and Prosperity initiative.

The French government released a video of her trying to make conversation with Canadian Prime Minister Justin Trudeau, French President Emmanuel Macron, IMF chairwoman Christine Lagarde and British Prime Minister Theresa May.

She appeared on camera in a video published by the White House giving a readout of a trilateral meeting between the President, Indian President Narendra Modi and Abe, a responsibility traditionally carried out by a national security staffer in a written statement. In the video, Trump speaks directly to the camera about the "productive morning, to say the least," occasionally averting her eyes.

Trump also traveled with the delegation to Seoul, where she attended the dinner at the Blue House, had a discussion on women in the global economy with South Korean Foreign Minister Kang Kyung-wha and visited the DMZ, where her father shook hands with North Korean dictator Kim Jong Un and became the first sitting US president to step into North Korea

Trump's national security adviser was absent from the stop because an aide said he had already departed Korea for a scheduled visit to Mongolia to "discuss regional security, infrastructure and economic issues." And Pompeo remained largely in the background during the high-profile trip, only appearing on camera behind the President as he made closing remarks. But while her father met with Kim inside for approximately 50 minutes, Trump crossed the line into North Korea -- inside a blue shelter and away from the cameras -- while senior officials like acting chief of staff Mick Mulvaney waited outside. Asked by a reporter in the traveling press pool how North Korea was, she replied, "Surreal."

Accountability

Ivanka Trump previously raised eyebrows among Trump critics during her attendance at the 2017 G20 summit in Hamburg when she briefly sat in for her father during one of the meetings with world leaders. She has since become more neatly tailored to issues of women's economic empowerment and workforce development. Yet she still advises her father on a myriad of issues internally. She has been one of his longest and most-trusted advisers, starting with her time in the family real estate business.

Former Obama State Department spokesperson, Pentagon press secretary and CNN analyst John Kirby said that her outsized role during the trip raises "legitimate concerns" regarding the transparency of Trump's responsibilities as a White House official, and, subsequently, her lack of accountability mechanisms as an unelected staffer.

"It raises real questions about what policy issues does she have a stake in and does she have authority to speak for the United States on," Kirby said to CNN.

To him, her visibility is an "optics problem" for the administration.

"I found it fairly stunning that she had a seat at so many tables and was involved in so many bilateral policy discussions," he said. "It certainly doesn't help America's standing on the world's stage as a democratic representative government because she wasn't elected by anybody and hasn't been formally appointed to any position."

White House deputy communications director Jessica Ditto said it is "sad but not shocking that the haters choose to attack Ivanka Trump, a senior adviser to the President, when she is promoting US efforts to empower women through strategic partnerships with world leaders." The spokesperson did not respond to questions about Ivanka's role in foreign policy discussions, which are not in her portfolio.

The Ivanka Influence

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Both Ivanka Trump and her husband Jared Kushner have enjoyed a wider range of access since Mulvaney replaced John Kelly as chief of staff . Mulvaney has maintained a hands-off approach, unlike his predecessor, and does not try to limit their influence or access to the Oval Office. Officials attribute this as one reason he has had success as chief of staff. While one official described Mulvaney as seeking to "empower" the two senior aides for their own benefit, others in the White House see it as a shrewd move designed to keep him in his job longer. So far, it has worked for Mulvaney, who recognizes that Trump and Kushner are the only aides with essentially full job security.

In turn, Trump and Kushner have viewed Mulvaney as an ally in the administration, even if the chief of staff's own influence with the President is somewhat limited. While Mulvaney is trusted by key members of Trump's inner circle, the two men have little chemistry and interact less frequently than during other chiefs of staff's tenures.

Her camera-facing role this week comes amid speculation about her political future.

"If she ever wanted to run for president," Donald Trump said in an interview with The Atlantic earlier this year, "I think she'd be very, very hard to beat."

But the President told the magazine that his daughter hasn't expressed any interest in running to him.

At the conclusion of the trip's events on Sunday, the President called his daughter and Pompeo to the stage as he addressed troops at Osan Air Base.

"Has anyone heard of Ivanka? Come up, Ivanka. She's going to steal the show," he said, calling the Pompeo-Ivanka duo "Beauty and the Beast."

This story has been updated with White House comment on Monday.