If you are signed into multiple accounts on GitHub.com, you'll be able to pick between them when you sign in using the device flow. This authentication method is typically used for console applications, like the GitHub CLI and remote use of VS Code.

An account picker showing 3 accounts - one signed in with a green "Continue" button, another signed in with a "Select" option, and a third that's signed out, with a "Sign in" button. Above the picker it reads "Device Activation"

For more information about using multiple accounts, see "Switching between accounts".