With the power of its image dedicated artificial intelligence algorithms, Facebook is doing the job that smartphone manufacturers (unfortunately) don't do by deploying unique features.
After the 360° photos, after the "bokeh" blur on Live videos (which has strangely disappeared a few weeks ago), and even after the Portrait mode in its subsidiary Instagram's application, Facebook recently announced the 3D Photo mode for iPhone.
This feature has been in the process of being deployed for a few weeks among Facebook users, and it arrived today in my application.
To use it is very simple. You must launch the Facebook app to create a publication. By clicking on Express yourself at the top of the screen, you bring up a drop-down list of options in the lower half of the screen. Scroll down this list to "3D Photo" and then select a photo in Portrait mode of your film, validate, test the result by rotating your iPhone in several directions, and if you like the result, you can publish, as I did on this post with this raw, untouched photo.
If you don't have access to this feature, be patient and monitor your Facebook app for updates, it should arrive soon.
Remember that this option is only available on the iOS app, for iPhone with dual sensors, namely iPhone 7 Plus, 8 Plus, X, X, Xs and Xs Max.