I think some of the responses may be confusing 'passing' and 'accepted'. I see passing as being identified as cis by pretty much everyone. Being identified as trans without negative experiences is being accepted. I doubt I'll ever achieve the dream of being seen as a cis woman by many, but I will be happy if I can be accepted as a trans woman.
From learning photography, I found that initial perceptions depend on some key features. It's not just what you look like, but how the observer assesses a scene. In a photo of a person, the eye is the first thing an observer is drawn to, so it must be in focus. Some say this is instinct as the eye can inform if someone is friendly or foe. The next thing is the setting. In typical female settings, the observer expects to see females, and so will initially see everyone as a female, unless there are obvious contradictions. Same for male settings. In a photo of a person with long hair pushing a shopping trolley in a supermarket, initial id will be female. Things that will cause a second look in a photo are those which don't complete the story. If the trolley pusher is coming into the photo, ie there is an aisle ahead of them, the observer uses the information presented to complete the story, ie person shopping. If the trolley pusher is leaving the photo, the observer doesn't have the information to see the immediate future, and so a question is formed.
Presenting as other than your birth gender uses the same principles. If you basically look consistent with the story, the observer will be confident of the immediate future and move on. If there is an obvious inconsistency with the story, the observer will stop and question to determine the immediate future before moving on. The key elements are distance, the scene and the eye. It comes back to instinct. At a distance, another person is less threat, but as you get closer, it is natural to quickly look for signs of threat, so going to the eye is first. If the eye doesn't show threat, then the rest of the package will be assessed. This is why young teen girls are so good at making trans people. They are honing their visual defences, and are sensitive to anything which doesn't complete the story.
Passing as cis is great, but being accepted despite doubt as to your gender may be a greater achievement as you have done things to cause people to welcome you into their world which may be a stronger relationship. Not passing and not being accepted are what most of us fear.
Enough rambling, over to your thoughts!!
Allie