All too often there are sessions like this in movies (which often depict real life) that turn into sexual activity, exploiting, unwanted/unwelcome touching, and even rape. Gerald painted the woman’s sexual organs in a juxtaposed psychological manner. It serves as an indicator in this piece. The green, we associate with “GO”, but if you really pay attention that green is an “X”.
So many times things are often misinterpreted due to our own selfishness, desires and not seeing with our “eyes”. Ironically in some cases, the subject matter often doesn’t even fit into our own tastes or ideals of beauty. Despite that, we use the GREEN as an excuse to GO fulfill our own selfish physical desires, but what the subject is really/ultimately conveying, even though the indicator isn’t RED, is an obvious NO.
In summary, the subject is volunteering to pose nude for the painting session, but nothing beyond that. The posing is neither an implicit contract to anything more, nor is it an invitation to anything further.