Didn't read through all the responses, but I am firm believer that this is related to DHT. Obviously when you are feeling confident, you carry yourself differently and people pick up on that, subconsciously or not. Men and women are no different in this regard- we all size each other up without even realizing it. Sexual attraction comes along with this and while the studies on pheromones are limited in relation to hormones, they have done some with goats and DHT and found that there is a pheromone secreted when DHT is high and causes an increase in attraction.
Personally, I believe this 100%. I am on TRT so naturally my wife all women cannot stop coming on to me. j/k

But in all seriousness, when I run a cycle of epiandro, I almost immediately start noticing a lot more flirting, extended casual conversations, and general increased accommodation. I am an extrovert to start with so I have no problem talking to people, so I notice when it is more than normal. With my wife, I'll notice that 3-4 days after starting, there is a very noticeable change in behavior. She'll walk by and slap my ass in the kitchen, jokes around more, and generally is just very into me. And we've been together for 22 years!
In the gym, I have had so many guys engaging in conversation about how long I've lifted, making complimentary comments, and general interest. And I am the guy that goes to the gym, does my thing, and leaves. No idle chit chat and socializing, so I normally don't talk to these people.
So yes, I believe there is definitely something to females (and people in general) subconsciously noticing when someone has high testosterone/DHT.