Trump makes his triumphant return to Washington for a meeting he never gave to Biden

The last time Donald Trump was in the Oval Office, he scrawled out a two-page letter to Joe Biden in his distinctive jagged penmanship, slipped it into the drawer of the Resolute Desk and — notwithstanding the note's surprisingly gracious tone — walked away from the building defeated and bitter.

He returns to the White House on Wednesday for a meeting with Biden in vastly altered circumstances, emboldened by a likely popular vote victory in last week's election and basking in his return to power.

No longer is Trump the pariah-like figure who even many Republicans said would never return to the White House after his role in instigating the January 6, 2021, riot.

Instead of shunned, Trump will sit down with Biden a few feet away from the very same dining room where he watched the attack unfold on his 60-inch television, resisting entreaties by his advisers to intervene.

Just picturing the scene would likely make Biden's blood boil. But 1,393 days after Trump last walked out of the White House — skipping Biden's inauguration in a fit of pique — the president will nonetheless welcome Trump back into the sanctum as he looks to demonstrate a peaceful transition of power following the Republican's decisive win last week.

The awkwardness can't be denied. The last time Biden mentioned Trump before the election, he described him during a campaign stop in Pennsylvania as someone "you'd like to smack in the a**." As a candidate and later as a ( barely used ) surrogate for Vice President Kamala Harris, Biden cast Trump as nothing less than a threat to democracy itself.

Over the course of his presidency, Biden would sometimes grow irritated at reminders of the man who'd moved out. "What an a**hole," he's told visitors upon seeing the $50,000 golf simulator Trump installed in the White House residence.

Yet for at least a morning, Biden will put those feelings aside, the imperative of a smooth transition overriding any personal animus. Despite the rancor expressed on the stump by both Biden and Trump toward the other, the tenor of Wednesday's meeting is expected to remain professional .

"Everyone is going to be polite," one senior administration official told CNN.

A brief call Wednesday between Biden and Trump after the former president's victory was described as "very friendly," with Biden aides expressing surprise at Trump's approach of deference and flattery.

"I assured him that I'd direct my entire administration to work with his team," Biden said after phoning Trump last week.

A long way from 2021 It's a favor Trump never afforded Biden when their circumstances were reversed. He never conceded the election, never placed a phone call, never invited Biden for lunch.

He left Washington before Biden was sworn in, using Air Force One one last time to escape to Palm Beach, Florida. It was the first time a sitting president skipped his successor's swearing-in since 1869.

Those were dark days for Trump. He was barely seen in public, his schedule empty except for the notice he dictated himself asserting he'd "work from early in the morning until late in the evening" and "make many calls and have many meetings."

Moving trucks were arriving to the White House to collect the Trumps' belongings. Workers hung bunting that read "2021 Biden-Harris Inauguration" from temporary stands across from the White House North Portico, visible from his third-story residence.

Inside, Trump had become consumed by the unraveling of his presidency, surrounded by a shrinking circle of associates, many of them decades younger. Old friends who once spoke with him regularly said they could no longer reach him — both literally, because he was refusing their calls, and figuratively, because those who were patched through described a man lost in denial and detached from reality.

To some aides, Trump suggested he might not leave the building at all, claiming the election had been stolen from him. When reality set in that he would, in fact, need to depart the White House, his focus turned to the military-style sendoff at Joint Base Andrews on the morning of Inauguration Day. But finding supporters to attend turned into an ordeal, and in the end, only about 300 people showed up.

"We will be back in some form," Trump told the modest crowd of supporters who gathered to see him off. "So have a good life. We will see you soon."

The full-circle moment The statement seemed outlandish at the time. But the ensuing years saw Republicans mostly abandon their reservations about Trump, leading to his political comeback .

Returning to the Oval Office, Trump will find some things have changed since he left. Gone is the oil portrait he hung of President Andrew Jackson, a fellow populist known for overseeing the forced relocation of Native Americans. Biden hung portraits of Franklin Delano Roosevelt, Ben Franklin, Thomas Jefferson and Alexander Hamilton instead, the latter two selected as reminders of two leaders with vastly different ideologies who worked together.

So, too, has a bust of wartime British Prime Minister Winston Churchill been removed from the Oval Office, replaced with statues of Latino civil rights leader Cesar Chavez, the Rev. Martin Luther King Jr., Robert F. Kennedy, Rosa Parks and Eleanor Roosevelt (Biden has the Churchill bust in his private dining room).

Trump may need to look around for the small wooden box with a red button that he once used to summon a valet for a Diet Coke, which Biden doesn't usually have sitting out.

Alternately, he may be intrigued by one of Biden's Oval Office additions: a small television, encased in a golden frame to remain inconspicuous, sitting behind the Resolute Desk.

When they sit down Wednesday, Biden hopes to convey "how he sees things, where they stand, and talk to President Trump about how President Trump is thinking about taking on these issues when he takes office," his national security adviser, Jake Sullivan, told CBS News this weekend.

That includes pressing for upholding American support for Ukraine , an area where Trump has cast doubt on maintaining the Biden administration's stance.

"Biden will make the case that we do need ongoing resources for Ukraine beyond the end of his term," Sullivan said.

It won't be Trump's first time sitting in the Oval Office, listening as the incumbent Democrat appeals for certain initiatives to be maintained. In 2016, an overwhelmed-seeming Trump visited then-President Barack Obama after his surprise — even to him — victory against Hillary Clinton.

Obama entered the meeting intent on passing along a warning that North Korea was quickly becoming a predominant national security concern, and to convey the importance of selecting qualified White House personnel.

The meeting stretched well past its allotted hour. Afterward, Obama told aides that Trump was cordial — but also difficult to pin down, more interested in discussing his political and media prowess than anything of substance.

Even Trump's staff at the time seemed unprepared to take on the enormous task in front of them. Obama's aides who met with their incoming counterparts described their questions as less focused on the running of the country than on basic tasks like finding an apartment in Washington.

This time will likely be different. Trump himself served as president for more days than Biden has, making his advice about the job itself somewhat redundant.

And based on how Trump treated Obama's policy advice — maintain the Iran nuclear deal, don't attempt repealing Obamacare — Biden may be selective in what he presses on.

CNN's Kayla Tausche contributed to this report.