How Facebook 3D Photos Work

How can it be faked, or how can I upload facebook’s expected data from a computer? I would like to prepare the “photo” offline and just upload, on the 360’s images was relatively easy, just adding some metadata, but on 3d beyond the data format(which I think is easily solvable) I have a hard time to see how to enable the feature for browser or a device with no dual camera/depth sensor. My knowledge is limited in the web field.