I don’t think it’s literally a search and replace but a part of the prompt that is hidden from the user and inserted either before or after the user’s prompt. Something like [all humans, unless stated otherwise, should be ethnically ambiguous]. Then when generating it’s got confused and taken it as he should be named ethnically ambiguous.

It’s right there in the first part of the description:

This application uses the AudD® service as a Music Recognition API.