If user is handled by systemd-homed, the message typo is fairly long and pushes the input with buttons too much.
See image to get proper idea https://ibb.co/Dg8GW6G
Note that this behavior has already changed a bit: https://github.com/systemd/systemd/commit/d423294394a411a3fe98884993f9c1686edffb1b. The question body is not intended to hold arbitrary information, so this commit splits it into an error message and a new question.
This is still somewhat janky, though, as other authenticators would just return PAM_AUTH_ERR to let the PAM client know that authentication failed. gtkgreet's presentation of error message will need to be adjusted a bit to make this convenient.