So we use the same rule used by most social media sites, including Instagram and Facebook: female nipples or genitalia mean adult material.
In many others, including reddit itself, adult material can be part of the work.
In many workplaces no reddit image is safe.
You can include multiple images in one post if you use reddit's gallery feature.
To verify send an original photo of yourself showing enough of your body to match with your other photos face and nudity not required if the pics you post don't show them , holding a handwritten paper that includes your username, the subreddit name and the current date.