In the end Mary filmed her spot for the commercial and that's what we saw.

She stated that she 'agreed to be part of a fun and creative campaign that featured a dream sequence' as a way of distancing herself from the project, and appeasing to her disappointed fans. Yet she is still a black woman singing about chicken and doing exactly what @TOHOTFORTV is talking about, and by doing that she is at the centre of the part that some people find racist. Would her appearing in a 'dream sequence' have made any difference to whether or not the commercial is being viewed by some as racist? I don't think so, it may have even made it worse.

If she had found this commercial racist before singing on the dotted line, recording the jingle and filming her part I am sure she would not have done it. Would she have said anything had people not enjoyed the commercial? And would Burger King have pulled it? I guess we'll never know. In the end some people are going to be offended and others aren't, it just shows that in this day and age everyone responsible for producing anything viewed by the public really needs to understand their audience.