The #nsfw is not for your convenience, it is so that people can scroll through their feeds at work, or the library, and not shock anybody looking over their shoulder.
If you don't want to use #nsfw then, at least, put a benign first pic for the thumbnail so that people don't unsubscribe you because they can't have your 'artistry' embarrassing them at the library around a bunch of innocents.

This is not really debatable.
The community will enforce this standard on everybody for the reasons I stated.
You don't have to use the tag, you don't have to put a non-nude pic for the thumbnail, but when we flag it and downvote it so that it can't be seen by people that choose not to see it, then don't cry to us.
You were given the heads up.
Up to you to follow our advice.