Barack and Michelle Obama make first joint return to the White House for unveiling of official portraits

(CNN)- Former President Barack Obama and former first lady Michelle Obama will visit the White House on Wednesday for the unveiling of their official White House portraits -- marking their first joint return since they left in 2017 and the return of a Washington tradition last celebrated 10 years ago.

The pieces, which will hang inside the White House for decades to come, are the first official portraits added to the White House Collection since then-President Obama held an emotional, bipartisan unveiling ceremony for George W. Bush and Laura Bush in 2012.

Wednesday's ceremony in the East Room marks a rare occasion for a celebration among two presidential administrations inside 1600 Pennsylvania Avenue, where President Joe Biden and first lady Jill Biden are expected to convene a who's who of administration officials past and present -- from the unique vantage point of having served in both.

It was in the same room Obama awarded Biden a surprise Presidential Medal of Freedom in 2017, a teary ceremony that reflected the two men's deep mutual respect. While both like to play up their relationship in public, there are limits to their friendship, officials have said.

Stewart McLaurin, the president of the White House Historical Association, told CNN that the Covid-19 pandemic played a factor in the timing of the unveiling. The WHHA, a nonprofit organization, facilitates and funds the creation of the portraits.

"Covid impacted us two-and-a-half years ago, and I do think it's important for these (portraits) to be revealed at a time when the public does have access to the White House and they can be seen," McLaurin said.

While there's no hard-and-fast rule for when a White House portrait ought to be unveiled, ceremonies have often been hosted by a former president's immediate successor. And when in office, President Donald Trump never held a ceremony for the Obama portraits.

What will the Obama portraits look like?

Details about the pieces being unveiled on Wednesday are a tightly held secret, with artists and art movers signing confidentiality agreements to keep things under wraps before the big day. But the Obamas have often used art as a tool to express their tastes, so it should come as no surprise that their White House portraits are expected to do the same.

"There's going to be a somewhat of an evolution in these portraits over time ... and I think it's actually going to be exciting," McLaurin said in a preview of the upcoming Obama portraits. "I think this is going to be somewhat of a magical moment. I think it's going to be an evolution of art."

He continued, "We're now in the heading towards the first third of the 21st century. And I think in the mind's eye of most Americans, we see presidential portraits as these very traditional, 19th-century-looking-and-feeling portraits. But art and taste in art evolves and changes."

While living at 1600 Pennsylvania Avenue, the Obamas opted to highlight several contemporary and modern artists.

A Robert Rauschenberg painting replaced a portrait of a Roosevelt in the family dining room. Mark Rothko and Josef Albers works were installed. And Michelle Obama brought in work from Alma Thomas -- the first Black female artist in the White House Collection.

Since leaving the presidency, the Obamas have staked some of their post-White House careers in taste-making -- producing podcasts and award-winning films, as well as curating playlists and book lists each year.

For their portraits unveiled in 2018 at the Smithsonian's National Portrait Gallery (which are not to be confused with new official White House portraits being unveiled this week), the Obamas chose two Black artists with unique perspectives on African-American portraiture.

Amy Sherald, who painted the first lady's Smithsonian portrait, challenges conventions about race by depicting her figures' skin in shades of gray. Kehinde Wiley, who painted the former President, re-imagines Old Master paintings with Black subjects.

Traditionally, the two latest sets of presidential portraits are placed in the Cross Hall of the White House -- though Trump chose to move portraits of Bush and Clinton into the Old Family Dining Room -- which was essentially used as a storage room during his White House -- after feuding with both families.

Biden moved the Bush portraits and Clinton portraits back to the Cross Hall, but with a new Obama portrait, Clinton may have to be relocated soon.