Thigh high socks and femboy stuff used to be heavily associated with trans people, but due to its "anime" aesthetic and popularity on YouTube internet fascists have latched unto it. The same is starting to happen now with cottage core which originates in a desire to push back away from alienation born of capitalism by like living in a house with your close ones where you grow your own stuff, away from the city. Fascists are using the same aesthetic to promote traditionalist values, in a way that's like, they attract unsuspecting people by using the aesthetic, dilutes in their nauseating ideologies in a discrete way and progressively radicalise people. Same for ecofascism, they use the general climate of fear and anger at governments' inaction regarding climate change to propagate their ideas on eugenics among other things.

Basically they know how to identify codes and trends that resonate among the younger internet users on the most popular social networks, repeat them while adding in their ideologies and thus slowly recruit more people.