What I find fascinating about this is how gendered basic things like movement are - things you would think are innate... Boy's body language doesn't get policed like that
I think it does, it's the flip side. Men and boys are expected to perform masculinity, to the extent that men who don't, feel less like men. And other men sure as hell notice when a man is being one of the "boys" This is the way in which patriarchy entrenches gender binary positions, and is now both antagonistic to trans but the social force that propels it.
What I find interesting is that trans seems to do two contradictory things, it breaks down the gender binary and it perpetuates it. It reinforces gender stereotyping when men transition and fully try to adopt "femininity" because it supports the hypothesis that men and women should look and behave differently. It seems to challenge gender when trans people pick and choose, are fluid or refuse to fully transition. Although this then gives rise to the problem of shared spaces and safety.
Most feminists agree that we perform gender, it isn't innate or natural, and we need to challenge stereotyping. So I have some sympathy with this idea that men should be able to wear a dress and call themselves Sarah. I have a problem when Sarah decides to perform gender because this often caricatured expression reinforces the gendered way in which we should act, or at worst is used as a way to belittle and piss take the ways in which women are thought to behave.
I also think there is a correlation between the rise in men transitioning or adopting the gender identity of woman with the rise in young women now self identifying as bisexual. It could be argued that social forces shape sexuality and therefore discourage deviation from heterosexuality, and that human's are now far from what Marx would have called species being, we are the sum and total now of the human made social forces that condition us. The same argument can be made to show how new forces within advanced capitalism has commoditised the female form, privileging female beauty over male, in its quest to create new segmented markets. Now, when most products are sold with sex, and women are increasingly objectifying themselves and other women, it is only a small leap to suggest that this conditions our sexuality. This same process, I believe has given rise to the further entrenchment of gender roles but also to the rise in men seeking to act out their sexual fantasy as "the objectified woman" or to transition. The objectified woman, is the woman who displays her subordinated status by behaving and looking like the "object" in almost comically exaggerated ways, enhanced ,airbrushed, using obviously sexual body language and clothing to enhance her status as sexual object. Desirable, available, but aloof staring back at us from every paper, magazine and webpage, men desire her, she is the epitome of success, little wonder we have men wanting to be her.