It's from the original article:
"regularly roar and scent mark, mount other females, and display other very male-like behaviors such as killing the cubs of rival prides which female lions just about never do"
And yes gender roles are social constructs, but you seem to think that means they're imaginary or inconsequential things, when they're sets of instinctual and learned behaviors that have developed to better improve the survivability of the social group much in the same way adapted traits do for the individual.
Yeah, a foreign male may nose that out, but you're assuming that means she couldn't kill him, when the reality is males that would be roaming outside of their own pride lands are usually the adolescents who have been ejected.
And don't be childish - you know full well this a discussion about how people (and lions) identify and interact with their social groups, not what they wear.