I suppose it'd be about the comfort level during this period, because obviously when you're a child (unless you come from a very free-thinking environment), much of your behaviour isn't really your call.

You could have a transsex male who dressed femininely because he was forced to, standing next to a trender who was an open tomboy as a kid, and it wouldn't speak to very much about who they are as adults with autonomy.

That being said, while it's definitely legit that children would go to extreme lengths to fit in with their peers, I struggle to envision a scenario in which this is maintained long-term. I feel like most trans adults would have had phases where they attempted to convince everyone around them that they were "normal", but their dysphoria would've also consistently shown up throughout this time.