It began at dawn, with a Twitter post about flag-burning.

In a period of just over 24 hours, stretching from the early hours of Tuesday into Wednesday morning, President-elect Donald J. Trump raced through perhaps the most frenetic day of activity since the election. With a series of surprise announcements and impulsive public gestures, he brought into sharp focus the freewheeling and compulsively theatrical style he will bring to the Oval Office.

There was the incendiary pronouncement about the flag: After Fox News aired a segment about protests that included flag-burning, Mr. Trump suggested stripping people who burned the flag of their citizenship, even though the act is constitutionally protected free speech.

There were hazy but headline-grabbing statements of policy: Mr. Trump announced a tentative pact with the air-conditioning company Carrier to protect some jobs at an Indiana factory, and pledged again to sever ties with his real estate empire, without offering specifics.

There was a new and indiscreet round of tryouts for secretary of state, featuring reviews from the president-elect in something like real time. Having paraded David H. Petraeus, the former military commander and C.I.A. director, past a throng of reporters for a meeting on Monday, Mr. Trump dined on Tuesday with Mitt Romney, the Republican presidential nominee in 2012 and another candidate for the job.