What I think that happens: my insula attached to the default mode network and is feeding information into it. It gives the ability of being much more sensitive at certain forms of empathy.
I remember before I went in thinking: research says I'll be better at emotional intelligence when I do this, I wonder what will happen. 10 days later I realized I became a lot better at empathy. So my emotional intelligence did grow :)
There's quite some research on this, but I'm going to be lazy and simply recommend Search Inside Yourself.
Disclaimer: the experience discussed in this comment is one of the reasons why I chose my username back in the day. So I'm biased.
The issue is: the practice that I got was amazing, but the theory is... not worth listening to. Fortunately, it was cheap, so 10 hours of practice and 1 hour of entertainment (is what I called it) was fine.
Though, if others have other Vipassana retreats, then don't consider this one as better.
Also: I wouldn't go in expecting that you'll experience my description above. However, you can go in with the idea that you're training your emotional intelligence, somehow. It's up to you to discover how it happened. For me the effect was screamingly obvious. But I can't guarantee that it will be for you and if it isn't then it's tough to distinguish it from placebo. With all those disclaimers in place, the above website is where I did a retreat (3 times now).
I noticed the same struggle when I talk to more extroverted people abouth the problems when approaching people.
That sounds like a dishonest way of treating people, and might be a reason why some people prefer to be more introvert.
Look at it like this:
I have a friend.
Friends try to do good things for each other.
My friend seems different today than they are usually.
They are sad.
My friend likes getting flowers.
I want them to be happier.
I will say something nice and buy them a flower.
It cheered them up a bit.
I will ask how they are, because I notice that other people do that for their friends and it helps.
On the one hand you could say, hey that's calculated manipulation. Which it kind of is and that sounds negative and dishonest.
But there is nothing dishonest about it. It's something many people might do without even thinking about which is why it seems odd to spell out as a rational process. But if you don't get it intuitively, you may have to resort to a rational process to figure out how to cheer your friend up.
I used to work with young adults on the autism spectrum at a ymca camp and the higher functioning folks lacked the ability to intuitively interact with others- the same way I might not intuitively understand engineering problems. I get frustrated by them and don’t know what to do. Imagine if that is how you felt interacting with people on a very basic basis.