Seth Meyers has raised concerns about President Donald Trump’s mental fitness after a bizarre video showed the 80-year-old president stopping to wave and interact with no one while walking toward Marine One earlier this week.

During Wednesday’s episode of Late Night, Meyers discussed the footage and questioned whether Trump was losing touch with reality. “Donald Trump might no longer be able to tell the difference between what is real and what is fake,” Meyers said, citing the video as an example.

The footage showed Trump preparing to fly to Kansas for a campaign rally. He paused, raised his hand and appeared to acknowledge people near him. However, the camera zoomed out and showed that no one was present. The moment drew laughter from the audience.

“When the helicopter pilot saw that, he probably wanted to call in a new flight plan,” Meyers joked, adding that the pilot might instead have wanted to fly Trump to a retirement home. Meyers also theorized that Trump may have been waving at construction workers at the White House Ballroom, making a joke about the stalled project.

Meyers was not the only commentator to express concern about Trump’s cognitive abilities. Liberal commentator Harry Sisson wrote in reaction to the clip: “This is really concerning. Yesterday, Trump stopped walking and started waving at nobody as he was boarding Marine One. The camera zooms out and shows nobody is there. His mental decline is getting worse.”

Political commentator Brian Krassenstein questioned why Trump was not receiving the same treatment as Biden, suggesting that the former president would face greater scrutiny.

The footage and the reactions to it are not, by themselves, a medical assessment. Concerns have also been raised by mental health experts. Dr. Germaine Odenheimer, M.D., a geriatric neurologist and professor emeritus at the University of Oklahoma College of Medicine, has expressed concern about Trump’s cognitive abilities and explained why she believes they have deteriorated significantly. Although she suspects he may have dementia, she identified his irrational behavior as a reason for concern.

Trump, who turned 80 in June, has repeatedly boasted about passing cognitive tests and rejected concerns about his mental health or age-related ability to perform his duties. He recently claimed that the cognitive test he says he aced is difficult and suggested that his MAGA supporters might not be able to complete it.

Those assurances have done little to discourage critics who are calling for greater transparency regarding his medical reports.