Presumably those who exited but still appeared in the advert gave their permission to have that footage in the advert… interesting.
Possibly by walking past a sign saying “by walking past this sign you give permision for your image to be used in a carlsberg advert” or words to that effect? A bit like giving informed consent for a study, if you know what the study’s about you may try and influence it, whereas if you don’t you’ll give more normal answers.
would anyone enter/sit down at all if all the audience were black?
Odly, I reckon I’d be more likely to do that than a room full of bikers (based on prejudice I’ll admit, I know some black people, I dont know any ‘bikers’ thus I’d be more wary of them).