Presiding over his first State of the Union address as speaker of the House, Mike Johnson sat at center stage, just over President Biden’s left shoulder, with one of the worst poker faces in American politics.

His eyebrows arched and fell. He pursed his lips. He couldn’t decide whether he should stand up, smile or frown.

He smirked. He corrected himself. He sort of rolled his eyes. He looked down. He sighed. He shook his head. He swallowed. He smiled again. He looked amused and patient when he clearly intended to look serious and not pleased at all.

To be fair, another performer had seemed to miss his own cue first.

As is customary, Mr. Johnson banged the gavel when Mr. Biden stepped up to the rostrum. And when Mr. Biden began, “Mr. Speaker,” Mr. Johnson briefly leaned forward, as if expecting Mr. Biden to give him the opportunity to deliver the ceremonial introduction of the president.

Instead, Mr. Biden launched right into his speech, and Mr. Johnson nodded politely and took his seat.

He then had the high privilege and distinct honor of trying to control his boyish facial expressions for more than 70 minutes on national television.

“I am afraid he may have practiced it in front of a mirror,” said the presidential historian Douglas Brinkley.

Mr. Johnson had urged his fellow Republicans, ahead of the speech, to respect the decorum of the event, and to refrain from the disruptions that have become commonplace in recent years. He more or less succeeded at keeping his party under control.

But his own brows, lips and eyes were another matter.

Part of Mr. Johnson’s challenge was one of contrast. Seated to his right, Vice President Kamala Harris managed to appear both relaxed and disciplined, her face always on message.

As long as there have been cameras trained on presidents, House speakers have been more than just State of the Union scenery. They are often silent characters — particularly when they belong to the president’s opposition.

Paul Ryan joked that he practiced his own poker face for former President Barack Obama’s final State of the Union, Mr. Ryan’s first as speaker.

Nancy Pelosi was a foil for former President Donald J. Trump, alternating a sarcastic clap with an unflinching scowl. At the end of Mr. Trump’s 2020 address, she calmly stood up and tore his printed remarks in half, like a dissatisfied customer rejecting a bill.

And Thomas P. O’Neill Jr., in 1984, could be seen over Ronald Reagan’s left shoulder, leaning backward, rolling his papers into a tight tube, which he put down only to applaud.

Mr. Johnson did not touch the papers in front of him, and while he sometimes nodded in approval, he appeared to applaud Mr. Biden only sparingly — most notably, after Mr. Biden said no American soldiers would be on the ground in Ukraine, and when Mr. Biden quoted Reagan.

While Ms. Harris rose frequently to join standing ovations by her fellow Democrats, Mr. Johnson got no such exercise.

Still, at the end of the speech, Mr. Johnson both applauded and rose to his feet, shook the president’s hand, buttoned his suit jacket, and — as Mr. Biden lingered in the well of the House chamber — looked very ready to go home.