Reuters/Lucy Nicholson
Whether you hide tagged photos from your Timeline or simply leave tagged images pending approval in your Timeline Review, the truth is, if those images are still tagged of you in any way, more people can see them than you think.
Here's how it works
Facebook's Graph Search makes it pretty easy to creep on just about anyone, even if you aren't friends with them, and find tons of images of they are tagged in.
By simply searching "Photos of" with the name of the person you want to search, you can see any image they are tagged in, even if they hid it from their feed.
The caveat is if you are not friends with the person you are searching, you will only see images that are shared with the public or images that have have been tagged by a mutual friend or a friend of a friend.
You'll see all the images available, including ones that aren't hidden from their timeline.
How to keep your hidden photos hidden
If you want to keep your hidden pics under the radar you can simply remove the tag. This will make it so the images are not searchable.
You can also adjust your privacy settings for "Timeline and Tagging" so that when you are tagged in a post it doesn't share with anyone else but yourself. This will remove all tagged images from your Facebook page, only allowing you to view them.
Keep in mind, though, that those people in the original poster's audience will still be able to see the image if they perform a Facebook Graph search for your photos.