When you think of feminine energy you probably imagine women on heels, dresses, lipstick, red nails, girly, or pink, fluffy, silky, flowery image may be.
When I say feminine confidence you probably see a typical corporate woman in pencil skirt, suit, dressed expensive, hair done, rich, expensive look...
for fun: What do you imagine?
The brain will instantly create the reality based on the information it was fed with about the particular topic. And that will become your reality.
So probably feminine energy, feminine power, feminine confidence more likely then not will be associated money, wealth, power, richness, title, position, whatever rich and powerful or status looks like for you. Specially after we have experienced emancipation too. Or a combination of all.
Feminine energy has nothing to do with gender.
And feminine confidence has nothing to do with the above either.