That's just ranking, it has nothing to do with nsfw filter which completely removes it. The ranking algorithm considers lots of different things, like how often do you post (and tries to give everyone a chance, so that the front page isn't dominated by a single person), how much views your post gets compared to it's impressions (which measures engagement), how much you contributed to the community (you're one of the top contributors, so your posts are boosted a little). There's some randomness as well and some other aspects which we tune continuously.