The incident occurred during a speech by the American leader in Seattle. When he finished his reform speech and said goodbye to the audience, he turned back to shake hands. No one was behind Biden, though.
Then the head of the USA made one more quarter turn and extended his hand to the emptiness again. After realizing what had happened, the American leader turned to the audience with a smile and thanked everyone for their attention.
In the published footage, you can see that there was no one near the head of state. Afterwards, Biden turned to the audience with a smile and thanked everyone gathered for their attention.
It should be noted that the 79-year-old leader of the United States has repeatedly been caught in curiosities of this kind, which gave rise to rumors about his health problems. The day before, Biden, speaking in Oregon, misspoke when he said the name of a member of the House of Representatives, after which he apologized and asked to be referred to as “Joe Biden.”