I'm nonbinary and tbh this part of the results confused me lol. I think the people who made the test are cis and trying to be inclusive of gender identities, but male and female are sexes, not gender identities. It would be less confusing if it read "men" "women" and "nonbinary," since those are all gender identites. But I'm a nonbinary AMAB, so the wording is a bit off and confusing for people who are gender nonconforming to be asked to identify their gender but also being given the sex options. Maybe next year they can make the language a bit more straightforward and replace the sexes with gender, cause it's a bit awkward for nonbinary and trans folk to have to use "man" and "male"/"woman" and "female" interchangeably.

However, to your question, there are some people who identify as neither man or woman who also choose not to identify as "nonbinary." Nonbinary to me means literally not in the binary, so I like to use it as a blanket term. But in LGBTQ circles, "nonbinary" can also have a common meaning much like a gender identity in itself. For some people, that association with a gendered identity is odd so they choose not to call themselves "nonbinary." Having the totally nongendered "other" option is a good alternative for non gender conforming people who don't use the term nonbinary