Who are creative within a narrow, conventionally "girly" band of creative endeavors. Teen Boss would not be interested in a 15-year-old girl who invented a revolutionary new type of automotive engine, because it is not a magazine about girls with grease on their hands.
Girls who want to should be free to engage in those kinds of "girly" pursuits, of course. To each their own! But by focusing only on those pursuits, Teen Boss sends the message to girls who are interested in other things (like STEM!) that they're weirdos who are walking away from success instead of towards it in their own way.