I'm with -KA- on this one. With the harder stuff (no pun intended) like baby arms, etc. it gets deleted. With what I'll call "softer" stuff I'll usually let it slide.
I suppose since it's a grey area, even with the mods, don't be surprised if one of us lets a post stay, while another one sends it to Jihad, this has happened with my own posts from time to time. It's not a perfect science, but, as it is a technical rule violation, don't be upset if one of your posts featuring such content gets deleted.
You can always question the mod that deleted your content. It could be a situation where you posted 50 pictures, but if you remove 1 or 2 of them and repost, it would be fine.
Bottom line, we want you to post, and have a good time here, so follow the rules as you understand them and you'll usually find this forum is a rather welcoming place.