These are extremely beautiful shots. In regard to full frontal nudity... we do allow it in the community if it's tasteful nudity. We have zero tolerance for pornographic or too graphic material that includes genitalia etc. Since photography is an art, it can be difficult to know where the line of art and controversy can be tastefully balanced.
So, you can post frontal and nudity but if you have anything you think is cloe to the line, then you use the #NSFW tag and your post will be filtered to where only those that want to see your post will have the ability without any controversy from those that don't want to see that kind of content.
Based on your other artistic posts with nudity, i don't think you even need to use that tag. I would suggest putting a thumbnail that would be mild in that case though. You have your thumbnails down to an art too... so. Just wanted to clarify that topic for you and encourage you to keep up the great work.