Patriarchy is a gender binary, so there certainly are standards and even rules for what it means to be a woman, but it doesn't have the same level of backlash that it does for men and there is no name for it (unlike The Man Box). Think about the acceptance of "tom boys" even back in the 1950s and then what kind of reaction a boy who wants to dress in "girl clothes" and take part in interests that are considered to be feminine - it would range somewhere between raised eyebrows and getting beat up.

Also, masculinity is something that one must constantly perform. You just are a woman, but you have to keep proving your masculinity constantly. That's the main difference.