I've only seen it on tumblr as part of a genre label (most famously follow for more soft alligator) and it seems to be used, idk, for a bunch of characteristics that might have been described as "feminine" fifty years ago? floral, pastel, romantic, gentle, soft-focus, unthreatenting, nurturing, etc.

Except in the sciences and sff, where it basically means "focused on people and relationships instead of technology and ideas or war". Or porn where it means, you know, not hardcore. Or music genres but that's beyond me.