That was 1941. Then as now, some people chose not to see Africans as not fully human, but by no means all people. It was considered culturally appropriate to show Africans women bare-breasted and men wearing only loincloths. Because it was. That is how they dressed. You could still see photos of Africans dressed that way in National Geographic. If you go to Africa today you will find than when Africans perform National dances they still sometimes dress that way.
Seeing everything in the past through a total racist prism is modern propaganda.
Link to the book:
Sexton Blake Library S3 013 - One of Seven