President Donald J. Trump debates with House Minority Leader Nancy Pelosi, D-Calif., left, as Senate Minority Leader Chuck Schumer, D-N.Y., and Vice President Mike Pence listen during a meeting in the Oval Office of White House on Tuesday, Dec. 11, 2018 in Washington, DC.

The impression one came away with was that Pence was disengaged, even aloof.

Seated between Trump and Pelosi, the vice president sat stone still for the better part of 20 minutes, shifting his gaze between the speakers and occasionally staring straight ahead, never saying a word.

But this is not the Pence that many Americans saw on television Tuesday, during President Donald Trump's epic public brawl in the Oval Office with Senate Minority Leader Chuck Schumer, D-N.Y., and House Minority Leader Nancy Pelosi, D-Calif.

So far this month, Vice President Mike Pence has attended the inauguration of Mexico's new president, delivered remarks while the late President George H.W. Bush lay in state, and held two formal calls with U.S. allies — one on Friday with the British foreign secretary about the Brexit vote and another on Tuesday morning with the Iraqi prime minister.

To be sure, it's not unusual for the vice president to let the president have the floor while reporters and cameras are allowed in for the beginning of official events. But as Tuesday's meeting wore on, the contrast between Pence and the three other people he was sitting with became increasingly sharp.

Part of the reason things got so weird was that Pence had never intended to participate in the talks, a White House official told CNBC. Pence was there to listen, and then to relay information back to Capitol Hill about the status of negotiations.

As a matter of practice, Pence gives the president his feedback in private, the official said, and on a typical day, the two men have several opportunities to touch base.

Still, the extraordinary exchange in the Oval Office underscored, yet again, how different Trump's and Pence's public personas are. As the president grew increasingly angry, Pence stayed almost preternaturally calm and quiet.

Yet as soon as the meeting was over, it was Pence who remained focused on the high-stakes negotiations underway to prevent a government shutdown, while Trump turned his attention elsewhere.

Pence went to Capitol Hill, where he briefed Republican senators at their weekly lunch about what had just happened in the president's office.

While Pence was on the Hill, Trump turned to another pressing issue on his mind. The president took to Twitter to rail against former FBI Director James Comey, who has emerged as one of the president's principal antagonists in the ongoing special counsel probe.

In his first tweet following the momentous meeting, Trump wrote that Comey "had no right heading the FBI at any time, but especially after his mind exploded!"

Trump fired Comey in May 2017, telling NBC News' Lester Holt soon afterward that he was thinking of the Russia investigation when he decided to fire the FBI director. In turn, Deputy Attorney General Rod Rosenstein then appointed Robert Mueller to be the special counsel in the Russia probe.