So if you're worried — or just merely curious — there's now a Chrome and Firefox extension that will reveal all.
It's called Show Facebook Computer Vision Tags, and it'll show a list of labels that Facebook has assigned to your images. The tech giant has been doing this since April 2016.
The extension is also a way to see how good Facebook is at determining what is in your photos, accurately assigning the tags "sky," "outdoor" and "nature" to the picture below, for example. Read more...More about Tagging, Photos, Machine Learning, Facial Recognition, and Facebook