I would approach this assignment by being myself. If it offends me, it probably offends a group of people. I would try to approach but acknowledging that people may not be aware of the problem with the work but then I would state facts to support my claim that it's culturally offensive. I think it is important to address the issue directly because the respect for other people's culture is what makes society function. Moreover, this would allow the readers of my review to be educated in something that they may not know anything about.
I would address the issue directly in the review because that is just the type of person I am.
