We wouldn't necessarily proclaim President Donald Trump aan efficient multitasker, but the man has managed to turn his first official state visit to the United Kingdom into a two-for-one family vacation package as well. While Trump's youngest son, Barron, remained at home, his adult children Ivanka, Donald Jr., Eric, and (even) Tiffany, have all made their way to London to hobnob with the British royals at Buckingham Palace. Even in-laws Jared Kushner and Lara Trump, Eric's wife, made the cut. It not only marks the first time all four adult children have traveled with the president on an official diplomatic visit, but also stands as a rare occurrence for the adult children of any president in American history. State visits don't often double as family reunions, especially with grown children in tow, and the occurrence has certainly raised some eyebrows.

Of course, naturally, some observers believe it's Trump's way of equating his own family with that of the British royal family (who, of course, don't actually hold any direct duties regarding government policy). “He’s surrounding himself with his family in this kind of certainly royal-family, prince-and-princesses way,” Gwenda Blair, author of a Trump family biography, told The New York Times. “Just as traditionally crowned heads surrounded themselves with their progeny, he has surrounded himself with his progeny.” Some headlines, including at ABC News, have even wondered if they'd wish to be dubbed "the other royal family?"

According to the Times, the grown Trump children were only included in the trip about a month ago, though initial plans to have them fly over as a family on Air Force Once were dashed due to space, and the adult sons and daughters made their way to the U.K. separately, Tiffany Trump, for example, has apparently been elsewhere in Europe since late last month anyway, according to Instagram activity that placed her at a party during the Cannes Film Festival and on a boat with the socialite Peter Brant Jr. Kushner flew in from the Middle East.

According to CBS News digital's White House reporter Kathryn Watson, the executive branch has not bothered to offer any official explanation for the adult children's presence, especially the three who, unlike Ivanka and Jared, do not hold any official post in the administration.

Some don't really see why it would be an issue. After all, the Obamas brought their daughters to Buckingham Palace in 2011 (at a time that overlapped with Sasha's birthday).

"It's nothing new," Doug Wead, a George H.W. Bush staffer who also wrote a book on presidential children told ABC News. He noted that the two most recent presidents had minor children in the White House, "so we haven't seen what happens with older children."

Not everyone, however, think it's quite that simple.

Mark Weinberg, a former staffer in Ronald Reagan's White House, wrote in a column for CNN that the situation seems rather odd compared to Reagan's own visits to London, which did not include his adult children.

"During my years on the Reagan White House staff, I saw how the President and Nancy loved having their children with them, but it would never have occurred to them to have Michael, Maureen, Patti, or Ron join them on state visits abroad," wrote Weinberg, who called the trip "bad form."

We're not entirely sure how the British are interpreting the familial showing. In fact, apparently the BBC is just now explaining to its audience who exactly Tiffany Trump actually is with articles like, "Who is Donald Trump's daughter Tiffany?"