Much of Rick and Morty Season 6 Episode 2 takes place in an arcade game called “Roy: A Life Well Lived” first introduced to viewers in Season 2. Through some standard series shenanigans, Morty (voiced by Justin Roiland) has his mind taken over by the 5 billion NPCs in the game, while Rick (Roiland) becomes its main character, Roy, and tries to free Morty. At some point, in order for this to happen, NPCs named Martha and Rick/Roy coordinate with a consortium of world leaders that they meet virtually on a wall of TV screens.
After an unsuccessful meeting with the President of the United States, Martha and Rick/Roy argue in front of these world leaders, after which an empty chair just appears on the screen to the right of the screen in the upper left corner. The next few times that the wall of TV screens is visible, there are five people sitting in that chair, suggesting that their absence is actually an animation error.
AT Vulture profile, Rick and Morty animator Nathan Leitz said the show’s animation is very time-consuming, with a particularly tricky minute of one episode once taking the studio four weeks. With that in mind, the brief absence of a few silent minor characters is understandable, but it’s a point nonetheless that might interest fans tracking down such oddities throughout Rick and Morty.