Also, from a separate Washington Post article on the same subject:
Mostly, her prominence on a major foreign trip sends a message about who other countries should listen to or court, said Christopher R. Hill, a former U.S. ambassador to South Korea and other nations.
“It looks to the rest of the world like we have a kind of a constitutional monarchy,” said Hill, who oversaw nuclear talks with North Korea at the close of the George W. Bush administration.
“It’s increasingly problematic in terms of our credibility,” Hill said. “It says to our allies, to everyone we do business with, that the only people who matter are Trump and his family members.