He's having another manic episode!
Apparently the White House security staff doesn't consider that a problem.
https://www.mediaite.com/trump/kanye-west-storms-d-c-apple-store-gives-keynote-speech-on-table-says-hes-leaving-for-africa/
After days of odd behavior, he has lunch with the president, then wanders into an Apple store and climbs on the table to harangue the shoppers with a rambling "keynote speech". Apparently if you're rich and famous enough you can hang with the president even if you're obviously batshit crazy.