I think some people like to look at trans people, or think they're beautiful, because of relief.
Let's be honest: After being locked inside the wrong body, pushed into the wrong gender-expectations, and generally being held from being yourself, the relief of finally being able to be yourself in the outside world is brilliant!
So much more relaxing; as it a leaden weight was lifted from your shoulders. A new kind of contentment that has never been before. And yes; that shows.
Other than that, I don't see why the one person would be more attractive than the other because of something like this. Really. Well; perhaps some people harbour the illusion that they can be 'straight' with a trans-person, and still be with someone who is on the same 'gender-line' as themselves.. I dunno; just guessing, really.
All in all: I really don't think a topic like this is worth such a big deal. It's not about 'more feminine than thou;' it's nót a competition! I understand why there are so many negative responses to the remark of TS women being more feminine. I'd join the opposition, were it not that either side of this is nonsense, in my book.
We are who and what we are, and what we may become. That should be enough for anyone, right?