Let's take this one step at a time. You expect me to define feminine in words. All I can do is provide examples but this gets us very close to all sorts of issues with gender perceptions that make people uncomfortable. But since "feminine" is a gender issue, not sex, we have no choice.
1) I think it is considered feminine for a boy to run with his arms and legs in certain positions - usually involving too much flailing. Too much wrist movement is what makes it into the movies. Its basically joint looseness.
2) There is a feminine way to smoke a cigarette, you should know what I mean.
3) There is a feminine way to stand, I'm thinking hands on the hips, wrists touching pelvis even more so.
4) Skipping I imagine is considered feminine by many, for a boy that is. I know parents that won't let their sons wear red - too close to pink. They'd die if they saw them in full on skip.
This is all culturally mediated so it may differ from region to region (but I doubt it).
If you saw a guy in the bar doing the river dance, you know where the upper body doesn't move and they kick their hands by swinging their legs up and out - well I doubt that plays well in many parts of the USA college scene. Note that this kicking the leg up and out is sort of what we are talking about here.
Sauron is in the very early stages of a squatting posture with that left leg positioned that way, and a full squat is one step away from a stretch and a squatting stretch is one step away from a ballet move (which some consider feminine).
I still really like the art of course, but Woodsy wants details.