Theres a movement to use the term 'compensations' rather than masking, as most people adapt/mask to some extent so it can sound a bit meaningless.
I would say the difference is the level and the success. Eg if I were to go to a nightclub, it isn't just that I wouldn't like it, I would struggle to function the next day (and not due to a hangover!) Anything too over stimulating and I can't be around people and struggle to speak for a while after. It's like the worst brain fog. My adult equivalent is if I have to go to a big conference, I have to have a 'buffer' the next day of quiet work without having to do small talk,I would really, really struggle without that.
Whether socially or at work, my compensations would involve lots of mental work - eg the nightclub, (if I were to do such thing!) would include researching the venue, layout, times, etiquette, making plans and contingency plans, rehearsing socially acceptable conversations, and struggling if anything didn't go to plan (eg the dress code was different to what I expected, or new people were invited I didn't know about) I would also have a plan about how to deal with being overwhelmed (like the hiding in the toilets, a rehearsed phrase for when I wanted to leave)
With all the above, I'd expect to be half as successful as my friends, eg to be seen as a wallflower, awkward, not making new friends.
Anything like that would take a significant amount of mental energy in preparation, during the event and recovering after, hence it being more than just putting a smile on and trying to fit in. Similar to how we all get tired if we have to walk up lots of stairs, but someone with MS or CFS is going to plan for a day where stairs are involved very differently to someone who just is a 'bit unfit'.