During a conversation with George Lucas at the 2024 Cannes Film Festival, the 'Star Wars' creator addressed some longstanding criticisms of his franchise for a perceived lack of diversity in its cast. 'They would say, ‘It’s all white men.' Most of the people are aliens!' he noted.
It’s a joke. The op basically says that looking if a race is represented enough is as arbitrary as looking for if a specific blood type is represented enough. Or something along those lines, joke can be enterpreted in varying degrees of severity.
A “what about…” joke with a sarcastic undertone.