And I mean if someone that isn't the artist does it.

If it's behind a paywall, it's paid content. If the artist provides a way to access it freely, it is not.

And if only is a uncensored part of an already uploaded post that is partially censored? can't it count as 3rd party edit?

nanomecho said:
And I mean if someone that isn't the artist does it.

Only if it's someone with permission to post it publicly. Stuff gets leaked from pay sites, and there are twitter accounts that solely repost whatever thematic images they find without regard for where it came from (or when trying to find who made it), so if it's something the artist has behind a paywall, and it's posted publicly by a random account that's not the artist, commissioner, or character owner, there's a good chance it's leaked content.

nanomecho said:
And if only is a uncensored part of an already uploaded post that is partially censored? can't it count as 3rd party edit?

I'm not 100% sure, but I believe I've seen images removed that were uncensored by a third party when the artist already has uncensored versions behind a paywall.