I saw some person (?) the other day who made me do a double take.
Greeted me with a friendly hello, was out walking dogs, waiting to cross the street and for the signal to change.
The face was superficially female, the hair was long, the voice not too deep, but I noticed the heavily-muscled arms first.
And when this person walked down the street, watching his/her back, I noticed the obvious lack of hips (very narrow hips) and a funny twisted gait, as if it had a fanny pack sewn to the lower front of its clothing.
Some - some - “trans” you would not notice in anyway on the street. They could have but do not neccessarily have noticable physical attributes that seem out of kilter with their DNA assigned sex.
The essentional problem is a mental one, no matter how the body is or is not “reprsentative”, in the obvious ways, of their DNA assigned sex. They have to take hormones to make the beard appear or disappear, help grow or shrink breasts, ect., ect.