You’re not seeing things — that photo in your Facebook newsfeed is 3D. Launching today, 3D Facebook Photos use the depth maps from dual-lens smartphones to add dimension to an image as you move your phone. The effect is an image that pops as you scroll, without any specialty gear (unless you want to use your Oculus).
Source: 3D Facebook Photos Jump Out of the Newsfeed With A Turn of the Wrist | Digital Trends
It’s a more modern version of the 3D “wiggle” method made popular, originally, as self playing GIF files that “wiggled” back and forth between the left eye and right eye images.
3D image capture for this new feature works only on selected iPhone models having dual cameras. Facebook says other phones, presumably Android-based, will be added in the future.