On the final night of the Republican convention, just in time for her husband’s official nomination as his party’s presidential candidate, Melania Trump finally took her place by his side — sort of.

She was the last Trump family member to make her entrance at Fiserv Forum in Milwaukee, stoking the will-she-or-won’t-she anticipation to the end, arriving well after Ivanka Trump and her husband, Jared Kushner, who have also been largely absent during the campaign; Don Jr. and his fiancée, Kimberly Guilfoyle; Eric Trump and his wife, Lara; and Tiffany Trump and her husband, Michael Boulos. (Barron Trump, Donald Trump’s son with Melania, did not appear, but assorted grandchildren did.)

She walked in alone, in a red suit and towering red heels, hair down, bestowing queenly waves on an adoring crowd.

If the suit struck a chord, that may be because it had been seen before. Mrs. Trump had worn the ensemble — from Dior, with a New Look silhouette — in 2017, when, as first lady, she visited Paris with her husband for the Bastille Day celebrations. For anyone who remembers that suit, seeing it again was like sliding down a wormhole to the recent past when the Trumps occupied the White House — a further reminder, like the virtual White House projected behind Mr. Trump as he made his speech, of the point of the whole shebang.

Mrs. Trump was offering something of a preview of how she may again play her part. (Not to mention the fact that, despite Mr. Trump’s statements about manufacturing in America and buying American, she has never seemed all that interested in that idea.)