I noticed this too. I believe that Lemmy communities (and perhaps also Kbin magazines – I haven’t checked) don’t have a “default all posts to NSFW”. Thus, every individual poster must remember to mark their post as NSFW. If you look at the community view (https://kbin.social/m/gonewild@lemmynsfw.com), you’ll notice that most posts are marked as NSFW and properly blurred in kbin, but some posts aren’t marked NSFW.

So yeah, basically we need the ability for communities/magazines to be NSFW by default, as we can’t depend on posters remembering to do so. There will always be some times when they forget.

EDIT: I’ve confirmed that kbin magazines have an option to make the whole magazine NSFW by default. Can any Lemmy users check if there’s a Lemmy equivalent yet? If it exists, then it’s a community configuration issue. If it doesn’t exist, someone who knows where the Lemmy issue tracker is should go file a feature request.