Yes, this is interesting. First time I tried to transition every single time I saw a trans woman I'd think "oh God, so obvious, that's exactly what I'll be like"...rude I know, but I was only 23 and I was very much alone in terms of connecting with other trans folk as it was the early 1990s and there was no support forums like thus (wasn't even really an Internet!). Although it also occurred to me that I was overly attuned to the differences/"signs" but at the time my overwhelming fear was that I was going to stand out like a sore thumb.
After I decided to to transition I remained very aware of any trans woman in a public space (of course, there have no doubt been many I never noticed at all) but the one thing that slowly started to sink in through my massively thick skull was that I was the only one who seemed to have noticed them, other people were blissfully unaware. In fact, as I neared transition this time, if I did spot a trans person in public I started paying more attention to everyone else to see if they were reacting in any way. Nope, not all.
So unlike last time when noticing a trans woman would fill me with despair this time it started to fill me with hope. And indeed that does mostly seem to be the case, most people hardly give me a second look, if they look at me at all. Sure I've had a few people stare and look me up and down, but that may just as much be a "OMG what a tall woman" as anything else.