It is Pokémon Quest, a game that is on the Nintendo Switch
Source: The same thing happens in SWSH, Mustard was playing Pokémon Quest and it gave a very similar/exact same message when you interacted with the TV he was playing it on. The game features cube shaped Pokémon, a cube shaped landscape, and cube shaped everything, Also, put “a Nintendo Switch with a game featuring cube-shaped Pokémon” in the google search and see what happens.
