Former president Barack Obama and his wife Michelle returned to the White House for the unveiling of official portraits.

The pictures have a modern vibe: him standing expressionless against a white background and her seated on a sofa in the Red Room wearing a formal light blue dress.

“Barack and Michelle, welcome home,” President Joe Biden said before he invited the Obamas to the stage to unveil the portraits.

Some in the audience gasped, others applauded.

“It’s great to be back,” Mr Obama said when it was his turn to speak. He praised Mr Biden — his vice president — as someone who became a “true partner and a true friend”.

The artist whom Barack Obama selected to paint his portrait says the “stripped down” style of his works helps create an “encounter” between the person in the painting and the person looking at it.

Robert McCurdy likes to present his subjects without any facial expression and standing against a white background, which is how America’s 44th and first black president will be seen here for posterity, in a black suit and grey tie.

Mr Biden and first lady Jill Biden invited Mr Obama and the former first lady back to their former home to unveil their official portraits.

It was Mrs Obama’s first visit since her husband’s presidency ended in January 2017. Mr Obama himself visited in April to help celebrate the anniversary of the major healthcare law he signed.

The former first lady chose artist Sharon Sprung for her portrait.

The portraits do not look like any others in the collection to which they will be added, in terms of style and substance.

Mr McCurdy told the White House Historical Association for the latest edition of its 1600 Sessions podcast that his style is “stripped down for a reason”.

He has also done portraits of South Africa’s Nelson Mandela, Amazon’s Jeff Bezos and the Dalai Lama, among others.

“They have plain white backgrounds, nobody gestures, nobody — there are no props because we’re not here to tell the story of the person that’s sitting for them,” Mr McCurdy said.

“We’re here to create an encounter between the viewer and the sitter.”

He compared the technique to a session with a psychiatrist in which the patient and doctor tell each other as little as possible about themselves “so that you can project onto them”.

“And we’re doing the same thing with these paintings,” Mr McCurdy said. “We’re telling as little about the sitter as possible so that the viewer can project onto them.”

Mr McCurdy works from a photograph of his subjects, selected from hundreds of images. He spends a year to 18 months on each portrait and said he knows he has done “when it stops irritating me”.

Ms Sprung, who also was interviewed for the podcast, described feeling as though she was in a “comedy sketch” when she met with the Obamas in the Oval Office.

She kept sinking into the couch she sat on while they sat on sturdier chairs. Then the president “flicked” away the printed talking points she had handed out to everyone in the room.

Then she just “went still” and had to “gasp for air a little bit” when someone else in the meeting asked her why she paints. Then she started to cry.

“So who knows what put the interview over the top, but that’s how it went,” Ms Sprung said.

She had planned on having Mrs Obama stand in the portrait, “to give it a certain dignity”, but said the former first lady “has so much dignity that I decided to do it sitting just because… it was too much looking up at her. I’m that much shorter than her.”