I think masking is easily conveyed with words because everybody does it - other terms used are "code switching" where you talk differently to friends, family, parents, bosses, subordinates or children; "emotional labor", a phrase often used for service industry people (think receptionists) where people pretend to be in one emotional state (happy and cheerful) for the sake of their job or role while they really aren't. This is even worse / more obvious in the US where a lot of people can / do switch their personality on a whim, e.g. when picking up the phone.

What's different is that for neurotypical people they don't seem to be aware of it and it comes naturally, but for ND it's learned behaviour that costs energy and conscious effort to do. And they feel like they have to do it because society is used to people effortlessly doing it all the time, so if you don't you're considered off, or simply don't get to participate in society because you're weird/boring/scary. The latter is the worst, you're just yourself but people get uncomfortable around you. They won't tell you why nor just accept you (which is understandable, biological defense mechanisms etc), but you do become an outcast. Unless you play the social games.

> Presenting autism-coded behavior around autistic people is stress-free.

Anecdotal, but... not necessarily, any one person's behaviours can affect someone else negatively.

> but for ND it's learned behaviour that costs energy and conscious effort to do. And they feel like they have to do it because society is used to people effortlessly doing it all the time, so if you don't you're considered off, or simply don't get to participate in society because you're weird/boring/scary.

And of course, every now and then you fail to do it right and people think you were acting really weird but won't explain why.

I'd like to elaborate a little more on why "autistic masking" is different from "neurotypicals' masking".

For neurotypicals, masking is to exhibit behaviors that you subconciously know how to do because they are part of your natural range of behaviors. When a neurotypical is masking being friendly and happy in a social occasion (when they actually don't feel like it), they draw on their previous experience of having been friendly and happy in another social occasion. They know what it feels like, they know how to behave instinctively whey they really are happy and friendly, and faking it is only the effort of drawing from prior experience. For actors, this is called "the Method".

For autists, masking is emulating behaviors they wouldn't normally exhibit on any such occasion. They don't know how to do it, not subconciously, not instinctively. So they explicitly have to observe others, emulate their behavior on that occasion. That leads to two kinds of problems: First, they need to have observed this behavior, learned and practiced it, and need to know how to reproduce it correctly. Second, they need to recognize the occasion correctly, and not misinterpret their surroundings, the feelings and moods of others. And since autists also do have problems even interpreting their own emotional state (they do have emotions, but no intuitive way to know what they are at the moment) and even more the emotional state of others, the effort is far higher. Imagine an actor who is asked to play a totally alien role without any frame of reference and without prior experience, no do-overs and all the other people around him are also directors and constantly judging his performance and measuring it against their effortless instinct what it should look like.