Lock Screen Issue (Macbook Pro)

On my MacBook Pro, there are two users. Only one of the users was logged in. The computer was shut (closed, not shut down) and then opened by another person who wanted to log in as the other user. The lock screen showed up only showing the account that had been logged into previously. There was only the option to type the password or click 'Cancel' which resulted in the screen shutting off. There was no option to select 'Switch User' from that screen, so the first user had to log in first and only then could the account be switched. Why is this happening? Shouldn't there always be an option to switch the user when the lock screen appears, even if one of two users is logged in?