Trademark laws are about consumer protection which is why companies must enforce their trademark or they risk losing it. In this case, I initially thought Postwoman was a spinoff of Postman built by the same team (not sure why they would do this but I guess representation is all the rage nowadays). If a consumer could mistake the product as a different one then it's grounds for trademark violation.

Disclamer: I am not a lawyer but I have at least a high level understanding of trademark law.